I am having a problem with with printing from .Net 2.0 on HP LaserJet 10xx printers.
Occasionally (sometimes once a month, sometimes once a day) printer gets 'blocked' in such a manner that it can not print anything from .net 2.0.
When printDocument.print method is invoked, it throws InvalidPrinterException, even if printer has just been selected from printDialog. Printer is online and working (everything else can be printed on it), only printing that goes through .net is blocked.
I have discovered that problem is in the following registry key:
HKEY_CURRENT_USER\Printers\DevModePerUser
If this key exists, PrintDocument.PrinterSettings.IsValid reports 'false'. The moment this key is erased PrintDocument.PrinterSettings.IsValid is 'true' and printer is working. Right now I am solving this the following way: If printer is "HP" and PrinterSettings is 'false' then check if registry key exists, erase the key and then do the printing. Now, I am aware this is lame, but so far I haven't been able to discover why this happens. I emphasize that this only happens with HP LaserJet 10xx printers. Printing from .NET is completely blocked until this registry key exists.
Has anyone seen such error and if yes, what is the solution?
Edit: here is the registry key that bloks the HP1005 printer.
Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Printers\DevModePerUser] "HP LaserJet P1005"=hex:48,00,50,00,20,00,4c,00,61,00,73,00,65,00,72,00,4a,00,\ 65,00,74,00,20,00,50,00,31,00,30,00,30,00,35,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,01,04,02,01,\ dc,00,44,05,01,00,00,00,01,00,01,00,00,00,00,00,64,00,01,00,07,00,58,02,01,\ 00,01,00,58,02,01,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,01,00,00,00,02,\ 00,00,00,01,00,00,00,01,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,02,01,00,00,48,00,50,00,20,00,4c,00,61,00,73,00,65,00,72,00,4a,00,65,\ 00,74,00,20,00,50,00,31,00,30,00,30,00,35,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,20,06,00,00,ac,0b,00,00,00,00,00,\ 00,00,00,00,00,20,06,00,00,6c,06,00,00,00,00,00,00,12,00,00,00,ec,13,00,00,\ c8,19,00,00,01,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,01,00,00,00,01,00,00,00,03,00,00,00,00,00,00,00,64,00,\ 00,00,01,00,00,00,0f,27,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,01,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,01,00,\ 00,00,00,00,00,00,96,00,00,00,00,00,00,00,34,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,40,17,00,\ 00,e2,20,00,00,ff,ff,ff,ff,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 01,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,12,00,00,00,00,00,00,00,01,00,00,00,00,00,\ 00,00,01,00,00,00,01,00,00,00,00,00,00,00,01,00,00,00,00,00,00,00,00,00,00,\ 00,02,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,01,00,00,00,01,00,00,00,\ 01,00,00,00,00,00,00,00,00,00,00,00,02,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,01,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 40,17,00,00,e2,20,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,64,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,64,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,02,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,01,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,01,00,\ 00,00,01,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,\ 00,00,00,00,00,ff,ff,ff,ff,40,17,00,00,e2,20,00,00,01,00,00,00,01,00,00,00