I just recently got one about 2 weeks ago, an AK2 version 2.1, & the usb was dead. I tried my own 4gb Kingston & my little bros 2gb Toshiba sd cards, neither read correctly. It said that the sd cards were full, that they were in RAW format, & when i tried to format mine (i had just gotten it for AK2) it wouldnt ever format it. Mine was just plain trash!! But, the good thing is, i only payed like 20c extra for it, so whats 2 dimes compared to a working AK?
Since my micro sd came with an adapter, i just use a 21 in 1 memory card usb adapter from Wal-mart. I wouldn't recommend it, considering its like 20$, but i had it laying around, unopened, so i was ok. =P