Just noticed this in the log. No idea what was the cause, but it didn't affect Eclipse in a visible way.

Scala plugin version: 2.1.0.nightly-2_10-201203130553-6e8582e

Scala compiler version: 2.10.0.M2-0152-g5dca64cefe-2012-03-13
Scala library version: 2.10.0.M2-0152-g5dca64cefe-2012-03-13
Eclipse version: 3.6.2.v201102101200

2012-03-14 12:21:02,172 INFO [main] - ScalaHyperlinkDetector - detectHyperlinks: wordRegion = offset: 38717, length: 10
2012-03-14 12:21:02,172 INFO [Scala Presentation Compiler [Kepler]] - ScalaHyperlinkDetector - unhandled tree class scala.reflect.api.Trees$Literal
2012-03-14 12:21:02,222 INFO [main] - ScalaHyperlinkDetector - detectHyperlinks: wordRegion = offset: 38717, length: 10
2012-03-14 12:21:02,222 INFO [Scala Presentation Compiler [Kepler]] - ScalaHyperlinkDetector - unhandled tree class scala.reflect.api.Trees$Literal
2012-03-14 12:21:02,242 INFO [main] - ScalaHyperlinkDetector - detectHyperlinks: wordRegion = offset: 38717, length: 10
2012-03-14 12:21:02,242 INFO [Scala Presentation Compiler [Kepler]] - ScalaHyperlinkDetector - unhandled tree class scala.reflect.api.Trees$Literal
2012-03-14 12:21:02,272 INFO [main] - ScalaHyperlinkDetector - detectHyperlinks: wordRegion = offset: 38717, length: 10
2012-03-14 12:21:02,272 INFO [Scala Presentation Compiler [Kepler]] - ScalaHyperlinkDetector - unhandled tree class scala.reflect.api.Trees$Literal
2012-03-14 12:21:02,532 INFO [main] - ScalaHyperlinkDetector - detectHyperlinks: wordRegion = offset: 38717, length: 10
2012-03-14 12:21:02,532 INFO [Scala Presentation Compiler [Kepler]] - ScalaHyperlinkDetector - unhandled tree class scala.reflect.api.Trees$Literal