Not owning a Jornada 720 myself (I've either got older HPCs, or newer Pocket
PCs), the best suggestion I could make would be to either ask on the
newsgroup microsoft.public.handheldpc or on the website
http://www.hpcfactor.com , both of which are aimed at users of handheld PCs
like the Jornada 720.
Taking a quick look at HP's site on the Jornada 720, though, I found the
quick start guide. Are you using the serial cable direct to the 720, or the
optional USB cable & cradle, to connect your Jornada. Without more of a
description of the problem, the only things I could recommend would be to
double-check the connection settings. On the Jornada, go to Start >
Settings > Control Panel > Communications, click on the PC Connection tab,
and make sure it's set to use whichever cable you're using. On your
desktop, go to Activesync, and double-check that it's trying to communicate
the same way.
Jason M. Donahue
Dietz, Gilmor & Associates