[R] error window

[Klemens Vierlinger]

Hi,
I guess this problem is super-trivial but I dont even know where to 
start looking.
After I installed R on my new computer, R has a strange new feature. It 
shows any error messages not only on the promt (as usual), but also in a 
little pop up window which I need to click away before I can proceed 
(see: http://www.lifesciences.at/download.asp?id=1577&lid=1 )
How can I turn this behaviour off? I couldnt find anything in ?options 
and dont know where else to look....

cheers
Klemens

winXP on Dell latitude
R 2.6.1