I got crashes at the gild bank too sometimes and I do not use these addons.
But the crash happens as I select a new guild AND the guild bank withdraw panel is open AND there are shown many items (like the material filter is selected and there are plenty of materials to scan).
If I open the local inventory view (bank deposit tab) the crash never happens!
One possible solution to track this down would be:
-Check each of your addons which are using events if the guild bank opens
-Check each addon which is using EVENT_INVENTORY_SINGLE_SLOT_UPDATE etc.
-Write a debug message into the callback functions with the addon name (at the point where the callback funcitons really is executed, and not stricktly at the first line, which could be "if isNew == false then return end" or something similar that will stop the function.
-Maximize your chat window, play opening the guild banks and switching around until if it crashes and have an eye on the chat window to see which addons are actually called, in what order, how often, etc.
This would be an attempt but I guess as long as the chat won't be dumped automatically each x seconds you wouldn't be able to fully see what is happening
