Ok - I've identified the source of the problem.
The function defined in the WA_AppBuilder_VB.asp named
is constructed incorrectly in that it is trying to return a value for the previous function:
To temporarily fix it, go to the WA_AB_checkMultiInsertLoopedFieldsExist and change the instances of WA_AB_checkLoopedFieldsExist to WA_AB_checkMultiInsertLoopedFieldsExist and it will work correctly.
You may need to replace the copy or mark it in dreamweaver to cloak it so that it doesn't update it on the site.
Hopefully 2.07 will have the fix.