My BB receives and sends emils through my work desktop but Ive been trying to backup BB data on my home computer as well. It backs up fine but after backing upp data on my home compputer I can no longer send mesages from my BB ...they come back with an "x". When I go back to work and resynch on my work computer and generate a new key it works fine gain ...how do i keep my home computrer from messing up the bb ecryption but still synch data?

that's because the 2nd computer removed the policy that the 1st computer put on your blackberry.

So you mean we cannot synch with two different computers? With the second one I'd like to synch Calendar, Contacts, Notes and Tasks ONLY, not e-mails. With my Palm I synch both home and at office.
Is there a way to synch without generating a new policy?

It has nothing to do with a Policy. Desktop Manager does not apply a policy. The BES applies the policy.

Be very careful syncing contacts, notes, tasks and calendar in two places. You could mix things up big time.

It is possible that the security key is messed up - that is a common cause of not being able to send messages.

You need to get onto Desktop Manager connected to your corporate network, start DM and go into E-Mail settings and Security. Generate a new encryption key.

Other thing to try is to go to Options / Advanced / Host Routing Table.
Click the wheel and select "Register Now".