Not able to close custom edit form in ArcPad 10.2.2 using ok button

Summary of problem: I have problem with ArcPad in that the "ok" button on my custom edit forms is unresponsive when I am trying to add a new feature.

Project set-up: I am using ArcMap 9.3.1 and ArcPad 10.2.2. I have three point feature layers in a geodatabase within ArcMap ("centres","probes" and "active") which I am checking out in .axf format for use with ArcPad. Each of the three layers has an edit form in .apl format which I am linking to when I check the data out. I have a small piece of vbscript code in a .vbs file for doing some additions and subtractions to populate some fields based on other fields.This is called by both "centres" and "probes". The .apl files and the .vbs file appear to be correctly incorporated into the .axf file when I am checking data out. I also have a dropdown list in .dbf format which is accessed by the "centres" layer; I have been adding this manually to the relevant folder on my handheld as I could not see a way for this to be incorporated within the .axf. I also have a fourth point feature layer ("waypoints") which I am adding to my ArcPad maps as a separate .shp shapefile (because .axf format cannot cope with the autoincrement option which I require).

Layer editing: Both the "centres" and "probes" layers have predetermined points whose attributes are amended or entered in the field via the edit form. I also need the option to add new point features to each of these layers in the field and to enter attributes for these features. The "active" layer and the "waypoints" layers have no predetermined points, all features are added in the field.

Previous problems: I previously had several serious problems with the .axf file when using ArcPad 8 and ArcPad 10. These included all symbology for a layer disappearing when editing a feature, error messages ("Unable to save data due to error 80040E014") and the spontaneous, error-message-free loss of attribute data from a seemingly arbitrary number of previously visited point features. This latter (major) issue appeared to be caused when rapidly changing the selected feature. These problems all seem to have been fixed by updating to ArcPad 10.2.2, however this update has created a new problem which did not occur when using the previous versions.

Current problem: When creating a new feature in the "centres" or "active" layers on a handheld, the edit form correctly opens and can be filled in. However, clicking the "ok" button fails to close the form and save the new feature. The button flashes when clicked but the forms fails to close. I can close the form by clicking the red X/cancel button but not even the geometry of a new feature is saved. Furthermore, if I then open the edit form for an existing point in that layer, I find that the "ok" button has also ceased to function there. Closing and re-opening the map restores the function of the "ok" button for existing points. Trying to create new features within these layers in ArcPad on the PC simply crashes the application.

NB: I do not have any problems adding new features normally to the "waypoints" .shp file and I can add points to the "probes" layer which is in the .axf file, although this success seems inconsistent.

Solutions? The ability to add features in the field is fairly fundamental to ArcPad as is the ability to use .axf files, so I would rather not have to move the whole project over to standard shapefiles as this would prevent the easy collation to data from multiple fieldworkers.