What firmware? You shouldn't need to download any additional firmware for this card.You probably don't need to modprobe anything at all - it should be automatic.Have you bothered to read the wiki? https://wiki.archlinux.org/index.php/WifiI can assure you that the driver exhibits no such issues here.
stibi wrote:There might be some connection with this problem: https://bbs.archlinux.org/viewtopic.php?id=170008 ?Why do you think this is related? Have you tried the suggested work around?What have you tried? Have you searched for that error?