First of all, some details: WMP11 + the newest ffdshow + windows vista.
Now let's get to the root of my problem. When I watch movies, everything is ok. Problems start when I turn subtitles feature on with letterbox 4:3 - then I get two lines. One is up above, the other one - at the bottom. Some of you might be having problems with seeing those stripes, because it's all about monitor, but they are there and they are very annoying (see attached screen or here - http://img240.imageshack.us/img240/3478/aaaxu2.jpg\).
This problemu occurs only with letterbox 4:3 turned on (other ratios or letterbox turned off don't give those lines).