Comment 0 for bug 338991

Cards that use the ath5k driver reportedly "stutters" and "stalls" (lag spikes) while in use. This has been partially resolved by lowering the transfer rate to 24Mbits, however this isn't a proper fix, just a quick fix till this is properly resolved.

Full thread here: http://forums.geteasypeasy.com/viewtopic.php?f=12&t=616
Quick fix here: http://forums.geteasypeasy.com/viewtopic.php?p=4038#p4038