I noticed that the binary in the link above was for an older wpa_supplicant (0.5.11) and Desire and the new froyo's are on 0.6.10 of wpa_supplicant so i repatched and compiled.
For those with the writeable /system hack, just disable wifi, push this on your /system/bin and reenable wifi. Else push this at recovery time
adb push wpa_supplicant /system/bin/
I also changed the "(*)" prefix for adhoc networks as i didn't like the look of the wifi list so now it's changed to "(adhoc)" suffix for adhoc networks it sees.
Diff and binary attached below.