three computers ad hoc(p2p)

Why while my p2p connection is turned on through UTP cabel, why won't
the wireless work in the same time. Three computers are connected with
various manual-assigned ip-numbers.
When utp is turned off, wireless starts to work. 2-3-1 (2=laptop)
(3=main laptop)(1=desktop computer).Can't realize why 'program files' on
computer 3 are unaccessible for computer 2 and 1, there is no sharing
but the 3. see both 1. i 2. and see their files, and it can change them
if i particulary adjust them to do so. ??

Thanks .
mm