Good 'catch' on the ad-hoc not supported by Android! [nasty
infamous bug#82 imho]
**What version of Windo$e? <8? (M$ 'killed' adhoc in 8 grrr but there's netsh workaround)
How exactly did you set it up on Ubuntu? Here
's something that claims to work.
(there's a ton more [with the 'right' search keywords] but I don't have Linux wifi to play)
Best wishes! Let us know (others will be searching LQ for this in the future)!