With the Eclipse Plugin v2.6.2, both with Eclipse 3.2.2 and Eclipse 3.2
(fresh installation): When typing new parts, for example
System.out.println(), it's routinely not syntax highlighted, instead
it is colored with "Others" color (see in the Scala plugn settings).
Syntax highlighthing will occur later for example when:

- I change to another editor tab withing Eclipse and then back to the
  problematic tag

- When I put the mouse over something in the editor so hint bubble
  pops up. (Note that this event causes the outline view to collapses,
  which is also abnormal.)
  
- When the content assistant (Ctrl + Shift) pops up. (Note that on
  most places you can't activate the content assistant until the line is
  syntax highlighted. Certainly there is a common cause behind these.)

- Under Eclipse 3.2.2 only, when saving *sometimes* (I'm not sure what
  it depends on)

(I'm using Sun JRE 1.6.0_01, Win32)