The only advice I can give you is this:

If Windows 7 UAC is turned on, might be better if you install Poser anywhere other than Program Files. UAC can make Poser act "funny" if installed there.

In Poser preferences, make sure your search is set to "Deep".

To make sure your Radeon is the gfx card being used, right click on "My Computer" chose "Properties" and then "Device Manager" it should list both gfx hardware devices. Make sure the on-board video is disabled and the Radeon is enabled by right clicking on each one under "Display Adapters".

Laurie