alexwg85,
Unfortunately we can’t offer any help with issues like this that arise from customizations. In order to get to the root of the issue, we’d most likely have to do a full code review, which is impractical given our limited support resources.
Since this seems to be related to a javascript conflict, I would recommend starting your troubleshooting there and see if some of your custom javascript (or a plugin’s javascript) is conflicting in some way.
Hopefully that points you in the right direction to resolving this. Good luck!
-Casey-