Well, GrabImage() is also what I use for internally generated graphics and I haven't had any problems between Windows, Mac or Linux.
I've tried to have a look at your code see what it could be, but it's rather difficult to follow. If I get some time (which won't be until the weekend) I might see if I can discover what the issue is. If you fix it in the mean time, please let us know what the issue was so that us Mac owners can avoid it in the future.
I've tried to have a look at your code see what it could be, but it's rather difficult to follow. If I get some time (which won't be until the weekend) I might see if I can discover what the issue is. If you fix it in the mean time, please let us know what the issue was so that us Mac owners can avoid it in the future.