Eclipse Scala plug-in: "illegal cyclic inheritance"

I just updated to the latest Scala-IDE version on Eclipse, and it's highlighting loads of spurious "illegal cyclic inheritance" errors in code I know to be OK (it was before, and it still compiles and runs OK).

Any way to fi开发者_开发百科x this? If not, how do I roll back to the previous version? I don't see any options to roll back or download earlier versions on the Scala IDE website.

Thanks.

edit: Never mind, it spontaneously sorted itself out after about 10 minutes sitting there showing errors. Will leave question here in case else anyone gets this.

"Project -> Clean Project" always helps me when Scala-IDE is showing weird error messages.

Sometimes errors will show in the editor, but not in the package explorer. Things still appear to compile ok when that occurs.