whats causing my bags to do this?

There's an updated version of both three tab and all open banks in the Interface Pieces of EQInterface.

Does anyone know what, if any, functionality I would be losing if I got rid of MQUI_BagWnd.xml? I'd prefer to see all my bag slots and it looks like that .xml is updated to 10x40 slot bags, so I'm not sure if that's the problem or if it's a EQ engine limitation.

The updated version has the same problem.

It's not an EQ engine limitation - it's specifically related to the MQUI_BagWnd.xml file. Deleting or renaming it makes the problem go away, but then MQ2Exchange crashes the client. Not sure what else it breaks.

Yeah, I knew the updated version had the issue, I was just pointing out that there was a three tab as well as an all open interface piece that has been updated to include the extra shared bank slots.

If Exchange is the only thing it breaks, I'll probably be getting rid of it. As for my thoughts that it might be an EQ engine limitation, keep in mind that having the MQUI_BagWnd.xml file adds another 400 open bag slots to the display, even if they're not visible on the screen. Add in the 1280 from an always open big bank UI piece and it's at least a possibility.