Is there any way to create an ad hoc connection from pc to tablet??
One of the other files often associated with wifi issues is /system/bin/wpa_supplicant. In this thread they discuss replacing it with a patched version which also adds adhoc functionality Android Ad-hoc support hack/wpa_supplicant. However, this may introduce new issues when scanning. So if adhoc connections are not important, you may not want to try this potential fix.