Hi,
I'm finding I'm having similar issues. I'm testing out arcpad to see if I can put it into production for a utility pole inventory.
I found in the past I could have 2 files (poles, a points layer and noted area polygons layer) from the same geodatabase check out and edit fine. My pole layer has about 4700 points and the noted area layer about 403 polygons
With 10.02 I found I could only have one editable axf layer. IF I had two, the arcpad screen would freeze, navigation bar would be disappear and some other random errors would occur with the map screen. When I checked out only one database file and used a editable shape file for the other, arcpad would run along fine.
This behavior happened on both my PC and the geoXH 6000 I'm trying out.