Strange. The best way to debug that would be to debug the XSLT. Here’s how:
1. Right click the map in solution explorer and click validate map.
2. That will generate the output XSLT to a file and it will display a link to the file in the output window.
3. Open the file in the XML editor (Copy & paste the file path from the ouput window into “Open -> File”).
4. When the file opens, you should see a new “XML” menu option on the top toolbar.
5. You should see some for-each loops in the XSLT that control the looping. My guess is that these are a bit off.
6. Add a breakpoint at the top of the XSLT.
6. Click XML -> Debug XSLT. It will ask you to select an input file, and after that you can step through just like you were in C#.
By the way, you might try removing the looping functoid. Without the looping functoid, the mapper will take a guess at how the looping should work. I have found that in many cases it is right.