You need to "parse" the information out of the xml. Exporting the field contents might be putting in field and record delimiters that confuse the import xml parser.
If you have FileMaker Pro Advanced, there are custom functions that can do the parsing. Brian Dunning's web site has a couple like this one:
Looking at the ExtractData() custom function, it does not appear to be recursive so it might be possible to enter the body of the function into a normal calculation field and get it to work.
I have been messing with it for a few hours now, and it seems that filemaker is adding a few special characters into the export text. This is what is crashing the import xml parser. After viewing the crash logs, it is indeed the xerces xml parser that is causing the crash.
This custom function may be the best way to go. The problem is I was hoping to use the imported xml data to updated records via a match field. I will have to figure out a way to search all the records for a match, if one exists update the record with my data, if none exists create a new one.
I don't think it will be to hard to implement, but dosen't sound like it will be very efficiant. Any Ideas?