Can't sync even though i am connected using active sync ve..

On my new Ipaq bought yesterday everything was fine including syncing
with USB and IR - even after I upgraded to Active sync 3.7.1 . I
tried to install several programs at the same time (Adobe reader etc)-
the programs did not get installed since it said that the pocket PC
should have been connected during installation which it wasn't.
However , now I can connect(and even explore the PocketPc from the PC)
but it just doesn't sync and the message on the Ipaq4150 just refers
to the last sync. I tried a) system restore in case of a problematic
other program b) the advice regarding regsvr32 dll's c) soft resets d)
removing network connection in options and several reboots of the PC.
Basically clicking on wcesmgr.exe doesn't result in anything. I'm also
worried about reinstalling Activesync after removing it since there
was a strong HP warning on the new hardware saying i may never be able
to sync if i connect with the PC prior to installation of active sync
(which i didn't do the first time and it worked fine - but how will
the subsequent removal and reinstallation be treated is unknown to
me).Please help as I have spent a bomb on the 4150 and already stuck
on day two of its ownership.Many thanks in advance.