InfoPath Dev

I went into the properties of a List Box control and placed a filter on the (Secondary) Data Source Entry, and it works just fine, the values in the list box are filtered correctly. The filter looks like this:

/dfs:myFields/dfs:dataFields/d:SharePointListItem_RW[d:Email = xdXDocument:GetDOM("User Information List")/dfs:myFields/dfs:dataFields/d:SharePointListItem_RW/d:EMail]

But when I add a translate to both side of the equation, although InfoPath accepts it without error, after publishing I notice that the list box is now completely empty, doesn't contain any values at all. The filter looks like this:

/dfs:myFields/dfs:dataFields/d:SharePointListItem_RW[translate(d:Email, "ABCDEFGHIJKLMNOPQRSTUVWXYZ", "abcdefghijklmnopqrstuvwxyz") = translate(xdXDocument:GetDOM("User Information List")/dfs:myFields/dfs:dataFields/d:SharePointListItem_RW/d:EMail, "ABCDEFGHIJKLMNOPQRSTUVWXYZ", "abcdefghijklmnopqrstuvwxyz")]

I tested both Drop-Down and Multiple-Selection List Boxes, and they both exhibit the same behavior.

Any idea why simply adding a translate would cause this problem?

Thanks in advance for your help!

I keep thinking the issue is that with the translate, only the first item is being compared... It looks like you are comparing items from two different lists, is that correct? Can you just add a calculated column to each list with the lower case value of the field?