Java Printing API / Jasper Reports keep pipes and deleted temp files opened

Question

Using JDK6u21, JasperReports 3.7.4 and Tomcat 5.5.30.

Running "lsof" command on linux (debian) for my tomcat process is normal until the application start using the printing API / jasper reports. After the application tries to print something or simply listing the network printers these are returned for "lsof":

java    2398 root 3931r   REG    254,6        0  8400157 /usr/share/apache-tomcat-5.5.30/temp/prn3532611318651333850xc (deleted)
java    2398 root 3932r  FIFO      0,6          35748011 pipe
java    2398 root 3933w  FIFO      0,6          35751941 pipe
java    2398 root 3934r  FIFO      0,6          35751942 pipe

I just list this 4 lines, but it can get up to 15.000 pipes/tempfiles.

These are not generated by my application. But seems I forgot to close/free resources or could it be a bug in JasperReports or somewhere else?

TIA, Arth