I have found Eclipse 3.2.x to be extremely unstable in use. I can't remember the last time that it didn't crash at least once during a days work and often many times. Fairly often the problem is an out of memory error. Sometimes it is possible to shut down fairly gracefully other times the JVM just exits without warning. I have searched around for solutions and one that seems to work fairly well is providing the following JVM arguments:

-vmargs
-XX:MaxPermSize=128m
-Xms128m
-Xmx340m

It seems that more often than not the JVM is running out of Perm Gen space which is, by default, set to 64m. Some people seem to need to turn the MaxPermSize setting up to 256m to achieve stability but they also report using a large number of plugins. Configuring the MaxPermSize setting has certainly dramatically reduced the number of crashes I am experiencing. I would especially recommend these settings if you are using the web tools. They seem particularly prone to out of memory errors.