I had the same issue with adhoc connection (see this thread : http://androidforums.com/samsung-galaxy-s/132471-wifi-issue.html)

Apparently Android 2.1 does not support Adhoc connections; and is supported only in 2.2. So waiting for the official 2.2 update.

 

Hi guys.... I'm the new to the forum and a new droid owner...

Been doing my research lately because wifi tethering, in addition to flash 10.1, is my biggest priority for my vibrant...

I've heard that the 2.2 update, as of right now, will not support wifi tethering... Or at least there are some major issues with it.

Have any of you looked into rooting your phone? I'm thinking about rooting but i do not want to screw up anything where the 2.2 update will not install because my phone is rooted....

Any thoughts on my dilemma?

 

have you enabled your mobile ap setting? i tether to my ps3 all the time & apart from a little heat works great.