Have few tabs opened on the bank page. Withdraw the amount quickly on each tab and the system takes it as valid command from EACH tab So if i withdraw 50k from 5 tabs, i'll receive 250k even though i don't have that much in bank,.
I've put a potential hotfix for this in place in the Pro version, could you re-download and re-upload and see if it's fixed?
Technically this shouldn't happen seeing as the values are refreshed when you click the button, but if your database is slow then it could potentially have this problem...