A: 

OK, there is definitely something that I'm missing. From SysUtils:

function PackageInfoTable(Module: HMODULE): PPackageInfoHeader;
var
  ResInfo: HRSRC;
  Data: THandle;
begin
  Result := nil;
  ResInfo := FindResource(Module, 'PACKAGEINFO', RT_RCDATA);
  if ResInfo <> 0 then
  begin
    Data := LoadResource(Module, ResInfo);
    if Data <> 0 then
    try
      Result := LockResource(Data);
      UnlockResource(Data);
    finally
      FreeResource(Data);
    end;
  end;
end;

So, if you are getting this last error, your package does not have the necessary PACKAGEINFO resource attached to it. This is probably also the cause of your first error (created with a different version of Delphi).

Appologies for asking this, but did you create the package by selecting File->New->Package-Delphi? I'm asking, because this have all the hallmarks of a library that simply has the bpl extention.

If you are certain that the package was created in the right way, may I suggest that you search your entire hard drive for a DLL file of the same name. And all the bpl packages that you do find, you should execute the following for:

C:\Program Files\CodeGear\RAD Studio\5.0\bin\tdump.exe mypackage.bpl>mypackage.txt

In your mypackage.txt file there should then be a resource called PACKAGEINFO.

Alternatively, you can download filemon.exe from live.sysinternals.com, set a bds filter and spy on what the IDE is actually trying to load. It could very well be another package that is being loaded by your package and that this second package does not have PACKAGEINFO attached.

Cobus Kruger
No need to apologize for asking *anything* -- I appreciate you input / ideas here, and will try them.
Jamo
Wondering if your "this have all the hallmarks of a library that simply has the bpl extention" might constellatte with the updated info above re: adding the dialog form...?
Jamo
OK, well if removing the dialog allows the package to install, then clearly the problem is not with the package being defined incorrectly. I'm still curious to know what TDUMP shows you - on both the broken version of the package and the working one that doesn't contain the dialog. If this is a Delphi issue of some sort, then perhaps you can try to counter it by moving the dialog into a separate run-time package of its own?
Cobus Kruger
The TDUMP (I'd not used that before btw) seems to look essentially the same as the other (working) BPL's I'd created. It's a pretty large text file. What in particular would I be looking for?
Jamo