set refresh rate to 0 , it will make it fly...
i have completed many big sierra games in shapeshifter (games like kings quest 7 and space quest 6..) and they are rather useless to play on a 040 mac (minimum spec is 040 25 , preferred is ppc) ..
i have no issues with refresh but i have heard others do, so check the refrewsh switch in videomodes menu... (where u set the cardtrick evd etc)..
cheers