I'm running Eclipse SDK 3.4.0 on Mac OS X 10.5.6.
Every time I try to install something new through "software updates", the message "The software items you selected may not be valid with your current installation" shows up.
So I'm going to uninstall it and re-install Eclipse.
Should I just erase the Eclipse folder or is there a way to uninstall it?
Actually Eclipse does create some other files not within it's directory which survive deleting it's directory.
In Snow Leopard, look in your user's account under:
~/Library/Caches/org.eclipse.eclipse
~/Library/Preferences/org.eclipse.eclipse.plist
Not sure if you need to turn on viewing of hidden files to see those.