I had no possibility to check the demo you posted (still downloading it at 100 Kb/sec)... The antialiasing seems to be a bug (and I already thought on solution)... I'll release the fix today in several hours...
EDIT 1: noticed that antialiasing "works" (On or Off?) 1 of 5 times when the application starts... THIS problem doesn't seem to be related to Asphyre - antialiasing is set every time you "InitDevice".
EDIT 2: I've checked your demo, noticed some faults with sprites (I think you SHOULD check the RealSize property for this), besides the application switched full-screen and windowed mode several times here - the screen blinked for a while... I'm not sure what you do but it appears that you either initialize the screen several times or switch "Windowed" property in run-time, when PowerDraw is initialized, several times or so... Application took some time to run here but since I could not understand the language well, when I selected first menu - it exited