My first character had upgraded the bank once, and deposited 2000 gold. The bank was full up on items. I created a second character who accessed the bank, but only 60 slots showed up and no deposited gold. When I went back to the first character, the bank was completely empty. I went back to the second character and it was just as i left it, no upgrade, no deposited gold, but had all the items minus the 10 from lost upgrade. I went back to my first character and now it mirrors what my second character has. So, after all this, I lost 2000 gold, my bank upgrade and the 10 items that went away with the bank upgrade.