You dont understand.
For a2sd ALL apps should be on phone. The a2sd script then AUTOMATICALLY moves them from the phone to SD-EXT. This is a better solution than froyo's "Move to sd", as it saves more space.
If you do use the froyo "move to SD" you are conflicting with a2sd. ...And why use 2 solutions to do the same thing when 1 is clearly enough?
The reason most people root initially is to utilise a2sd as it is better. It automatically moves all apps and it moves more of the apps than froyo can. Thats why it is so good.
To clarify further.
"Move to SD" moves part of SOME apps to FAT32 partition but leaves part of the app, dalvik cache and app cache on internal memory.
a2sd automatically moves all of the app and dalvik cache to SD-EXT. It only leaves app cache behind.
If you use both, a2sd automatically moves all of the app to SD-EXT. Then you move to sd, so you move part of the app again to FAT32. You're splitting the app and seperating it over 2 partitions. Whats more, some apps will not work properly and you wont be able to use them if mounted.
I dont understand why you would want to use 2 solutions to do the same thing that the 1 solution (a2sd) is already doing. Its a waste of your time and its messing the apps up.