After installing the JBoss Eclipse IDE (1.4.1e30), Eclipse (3.0.2 on Windows XP) stopped accepting closing brackets (square and curly).
I.e. I cannot enter them from the keyboard, but using auto-completion when I enter the correpsonding opening brackets.
These characters are obtained using AltGr+9 ("]") and AltGr+0 ("}") on a German keyboard.
All Editors in Eclipse are affected (at least Java and text). Other applications are unaffected.
Other AltGr combinations work fine, e.g. the tilde "~" (AltGr+"+").
When I switch to the English layout, I can enter the brackets.
Disabling the JBoss Plugin re-enables the keys, so I think it is a bug there.
I had the same problem.
See here for the solution:
http://www.jbossgroup.com/index.html?module=bb&op=viewtopic&t=61526