repeated mounting of USB device leads to different names

with my current 8.04 (rc) installment, I tried to create an ubuntu710 on a stick (pendrivelinux.com), but the I could not copy files onto the stick, as the name differs every time the stick is inserted

the first time it is recognized correctly as ubuntu710, the second time it is named ubuntu710_, the third time it is ubuntu710__ and so on, every time adding another _, and the earlier names continue to be in existence

so in my '/media' folder, I now have 7 'My Book' entries, of which 6 are not accessible, and 5 'Casper-rw' and 5 'ubuntu710' (4 are not accessible)
When opening these folders from the sidebar, the correct name appears on the window, but going back up, it shows actually the opening was from the '/media/ubuntu710_______'

When a terminal is opened and files are copied to '/media/ubuntu710' the files are read, and placed nowhere, and no error is displayed. the files are _not_ on the stick.