The Xomap X server (version 1.1.99.3-0osso21) had several problems related to XSP 

1) Rectangle intersection method returned wrong result
2) The initialization of the bounding rectangle used coordinates 
   that would have been perfectly valid. This resulted into wrong
   bounding box.
3) Server collected all damaged areas within one bounding rectangle and
   then flushed this using one operation. This is otherwise fine, but
   this easily causes a situation that bounding box clips DSP area, even though
   the individual damage areas wouldn't clip.

The issues 1) and 2) have been fixed in the Xomap versions of osso23 and later. Case 3) really doesn't affect N800,
but this hacker edition only. I made a quick patch that works as earlier if no DSP is active, but in a case of active
DSP each
damage area is flushed separately. This causes more ioctl:s than current 
approach, but it's unlikely that there will be too many other screen updates when DSP is in use. This patch removed
all unintended pausing issues experienced in the mediaplayer.