On my eMachines E520-572G12Mi I had similar behaviour if my wifi. Driver ath5k Chipset: Atheros AR242x/AR5007EG.
Problems disappeared when I set my router on a fixed channel in stead of "auto".
In Windows Vista the wireless connection was perfect.
(I don't know if this is the same bug, but in my opinion it is at least an imperfection of the ath5k driver.)
On my eMachines E520-572G12Mi I had similar behaviour if my wifi.
Driver ath5k
Chipset: Atheros AR242x/AR5007EG.
Problems disappeared when I set my router on a fixed channel in stead of "auto".
In Windows Vista the wireless connection was perfect.
(I don't know if this is the same bug, but in my opinion it is at least an imperfection of the ath5k driver.)