Acer Aspire 3502WLCi with Atheros AR5005G built-in wireless.
Ubuntu 7.04

After reading many sets of instructions, I have my wireless laptop working; even using WPA! On rare occasions, however, the Atheros chip will stop working, and cannot be re-activated unless I boot into WinXP. Once it connects thru XP, I can re-boot into Ubuntu and everything is good. Sometimes this occurs on boot up, other times it will stop working in the middle of a session. A read-thru of the dmesg log after a failed boot has an entry to the effect that "Hardware Version not supported" where the 'normal' activation information would be. Also, on the dmesg listing, it gives the chipset as "Atheros 5212", while "lshw" gives it as Atheros AR5005G.

Does anyone have any ideas what would be causing this?