Does that happen with all three printers?

Your Deskjet seems to have one really messed up preference set:
print.printer_HP_DeskJet_830C/832C.print_paper_size 3801127

I don't recall ever seeing that particular preference before. Right below that pref are settings that are normally seen for paper_size:
....print_paper_size_type & ....print_paper_size_unit 0

I don't know what that pref is for, but it sure looks like a faulty setting.

Try the reset described here for just that one printer:
http://kb.mozillazine.org/Problems_printing_web_pages#Reset_printer

Your above posted system details show multiple Java Console extensions.
You can uninstall (remove) the Java Console extensions and disable the Java Quick Starter extension, you do not need them to run Java applets.

See http://kb.mozillazine.org/Java#Multiple_Java_Console_extensions

See also http://www.java.com/en/download/help/quickstarter.xml - What is Java Quick Starter (JQS)? What is the benefit of running JQS? - 6.0

Disable the Java Quick Starter extension: Tools -> Addons -> Extensions
Control Panel -> Java -> Advanced tab -> Miscellaneous -> Java Quick Starter (disable)