If you follow depu's instructions, you should be able to get your wireless connection up & running without any problems, for as far as I know. I did the exact same thing a while back to connect to the wireless at our school (WPA2 Enterprise with certificate, EAP MSCHAPv2). It was already working when I still had PR 1.1 on it so...
Just make sure to go in 'Advanced', go to the tab 'EAP', tick the "use manual username" box and fill your username in again there. (all just like depu said). You can't select the certificate at the 'Select certificate' list in the PEAP settings (I couldn't select it there either) but that doesn't seem to matter, the wifi connection worked anyway...
(I seem to recall Ubuntu linux being able to request the needed certificate instead of having to manually install it, maybe Maemo does the same thing? don't know, but I do know it works )