Am also quite frustrated with the scala plugin on Eclipse and I can add a few more problems to the list:
- auto-complete only works some of the time
- the debugger doesn't work properly (especially when trying to debug scala xml)
- the debugger forgets breakpoints
- 'go to definition' doesn't work more often than not.
I'm glad to hear that Buildr sounds like a better alternative (on the build front anyhow), I'll give that a try - thanks!