Hi
I saw that once, only certain letters would transpose to odd but predictable stuff.
I had selected two 'eligible' keyboard sets (somewhere) at one point, and the 'alternate' was being used and was quite different than my expectation.
If this doesn't point you towards the solution, I can't guess at what's up. Try Fonts, Regional Settings, email settings, keyboard, and languages. One of them should help.
Good Luck,
JEFF from cowtowne.