My Checkbox is a Yes/No field in an Access Database, so if the box is checked, the value = TRUE. (this is what is shown in an Excel export)
However, I tried TRUE, Yes and 1. None of them showed the proper selection. That is when I noticed that on my DataAssist Update page the value was True as opposed to TRUE. I changed my rule to True and it works fine.
Just found this interesting and thought I would share it for others. Case sensitivity is not normally an issue with an MS Server and in this case, the case seems to change in ASP from it's native format.