VG:QotD has a similar problem in a couple of rooms. It isn't necessarily fatal.
In VG's case, it has to do with flood fills in the Pic resource.
When I have time, I'm going to fix the afflicted rooms, so VG will be up to original interpreter spec, but for anyone who wants to play other games that don't seem to work:
Open up the Pic resource for the offending room in AGI Studio. Look for very large fills. Delete this fill and use lines of the appropriate color to divide it into multiple sections. 2-4 should be adequate. Now refill these sections with the original color.
That should take care of these kinds of problems for a lot of new-school AGI games, I'm betting.
The other option may be that there are too many different painted parts in the game, like shading or intricate details. Try erasing these if the above technique doesn't seem to work.
If that doesn't work, then it may be a code issue, in which case, you'll have to ask the original developer to fix the issue, unless you want to go digging through the code.