applescript system events broken?

[tench]

weird, weird, weird.

my applescript which uses system events stopped working. i tried a newer, simpler one, only to discover that keystroking with system events now is completely on drugs -- it turns every character into an "a" except for numbers.

so:

display dialog "hello" -- works fine

but

tell application "system events" to keystroke "hello" -- outputs "aaaaa" in any application i use.

i tried reinstalling system events from pacifist, but to no avail. i hope i won't have to reinstall the entire operating system, because that would be tooooooo much to handle, so i was wondering if anybody had any idea what this could be about.

all best,
tench