I was asked to document a FAQ about Subclipse and cached passwords (my turn to play with the IT hat!). Here is the email (kept here for future reference).
Eclipse subversion plugin (Subclipse) will cache the username & password of the last user that did a successful commit with your eclipse installation.
This can be problematic if this user is not you, it turns out that until further notice all your svn commits will be under different username.
To resolve this issue, delete the following 2 folders:
rm -rf /opt/eclipse3.3/configuration/org.eclipse.core.runtime/.keyring
rm -rf ~/.subversion/
Then restart eclipse.
An alternative solution would be to kindly ask the busy IT department to change the svn password of the user under which your commits are being executed, then on first commit attempt Eclipse should prompt your for username & password, which will allow you to input your information.
Java Bytecode Assembly, Interesting concepts in the art of Computer Science/Software Development, maybe from time to time other pesky corp. related development issues.