xorg+kde4.1 compositie problem (nvidia card)

I'm not sure if it is x.org problem or kde4.1, but seems to me that mostly x.org.
I've recently updated my box so currently I have x.org 7.3.1, kde 4.1.1 on FreeBSD 7.0 (7.1 was released just day after I upgraded :( ). Nvidia driver is 177.82.
When I enable compositing in kde (using xrender, opengl compositing not work at all for me) everything work fine except one thing: when I play video with mplayer fullscreen (using xv driver) it show only small part of video and other parts of the screen are not refreshing at all. If I just maximize window everything ok, but pure fullscreen not work.
Same problem with opengl screensavers.
I tried some different x.org options, that was suggested in nvidia driver docs (for example DisableGLXRootClipping) but seems nothing helped.
Any suggestions?
i also have 177.82 installed, 7.1Rthough , and latest xorg stuff, but i only see problems in kde4; latest gnome, xfce4 and kde3.5.10 all work great. i also used compiz-fusion and linux-unreal tournament 2004 just fine. kde4 is a bit sluggish and compiz crashes kwin after a while ( i just loose widgets , rest still work).

i'd recommend 7.1 firstly, then use another desktop at least till 4.2 goes to ports ( in beta at moment)) or if u absolutely want kde4 now, try pcbsd7.0.2.

i am rather noob to fbsd , but have tried everything under the sun so far and my current setup is the best result so far. (also meaning, that, probably like you, i got nvidia driver 177.82 from their site and working better than 177.80 that is in ports at moment - unless updated this weekend )
Well, I think enough upgrades for me for the moment :)
Mentioned problem is not really important for me as I made shortcut to disable composite in KDE (thanks to KDE it is done in a moment with that shortcut) so if I going to see video fullscreen I just use that shortcut. And anyway composited desktop is not really important thing to worry about :) (but I just used to work with pretty desktop effects on my laptop with vista's aero).
By the way, at my laptop (vista as I mention above) when I open some video with mplayer vista automatically disables aero as it detects that mplayer's render is incompatible with it. And after mplayer closed it reenables it back. So it's almost same under KDE for me now, except for I must turn it off manually :)
Weird, I use GNOME with compositing turned on, Nvidia driver (177.80) and I can play full screen on MPlayer without any problems. I don't have compiz though..
I'm using 4.1.3 (compiled following these instructions: https://kf.athame.co.uk/access.php), and i also have this autostart after KDE:

nvidia-settings -a InitialPixmapPlacement=2

It helps quite a lot; there are no issues at all so far, everything behaves smoothly.
I remember trying 4.1.1 (with the same fix), and it felt as a somewhat bad experience; one thing i can remember is that sometimes framerate would drop to 0 and everything would freeze, when minimizing/maximizing windows.

I'd suggest to try the nvidia-settings command, see if that makes things better. If not, try 4.1.3.