Sapphire HD3850 AGP query

Hi,

Above card is running fine with games etc, just have one problem under
desktop:-

Embedded video content seems to be extremely slow when browsing certain
websites (while some others seem fine, such as the BBC site) - to the
point that even moving the mouse slows the video down; it seems that the
card is automatically underclocked when in 2D mode.

Is there a fairly straightforward way of removing this setting (I don't
use CCC), and would this resolve the issue? I've tried setting the GPU
clock back up to it's spec'd level with ATI Tray Tools, but it doesn't
seem to have any effect...

This is under Cat 9.6 on an Abit AV8 3rd Eye with an X2 4800+, 2GB RAM
an Windows XP x86.

Suggestions welcome.

Cheers,

Mark