I've experienced the same issue with a set of 30 acer travelmate's bought last year. After much ringing around it was confirmed that the model we bought didnt support starting with wireless enabled by default. It was recommended that we flash to the latest bios version which might solve the issue, but i was also told in the same breath that if anything went wrong we wouldnt be covered by the warranty .
I've actually found that pupils manage just fine starting the wireless themselves so for now I've left it as is.
Oh and i did notice acers inbuilt power management software starts the wireless itself after logon, but sadly i couldnt get it to work as a service running before logon.
