Ant debugger Eclipse 3.1 M4 may be buggy

I was very curious to test the much talked about ant debugger feature in eclipse 3.1 M4 release. It looks like this feature is buggy. At least I could not get it working. I use J2SE 5.0 and I had to upgrade to M5 release before the ant debugger started working. Upon enquiry I found this at eclipse site. Yes, skip M4 and kick tires on M5 instead if you want to save time