I bought my Palm Treo 700w from Verizon in mid February and had nothing but trouble with the Exchange ActiveSync for the first 45 days. For a few minutes the Treo would sync up fine, then at a random interval I'd get an ActiveSync error. Typically I'd see errors more often then I'd have a successful sync.
The error codes were all over the board, but I usually saw 85010004, 85010001 and mostly 85010014. There is a good source for Exchange Error codes at: http://www.pocketpcfaq.com/faqs/activesync/exchange_errors.php
Over the month I spent easily a dozen hours on Verizon's tech support. Typically they'd try and help for a while, trying all the obvious stuff, then they'd bring someone from Palm on board. Palm support was knowledgeable in all cases but one, where I had to end the call because the guy on the phone barely knew how to use the internet.
With all the support calls we'd soft and hard reset the Treo. They had me re-set all of my settings and such over and over. But they were stumped because the device would sync for a minute then stop syncing later.
The solution! My IT guy Matt Cardoza found the solution on his own. I'm not sure if Palm or Verizon even knows how to do it right yet. Basically our Exchange server is set up to use multiple IP addresses, but Outlook Mobile Access on the server was set to only use one IP address. This is why I could connect every once in a while but get errors the other times.
In his words: Our Exchange server has multiple IP addresses, however the IIS Instance associated with OMA/OWA was only configured to accept connections from 1 IP Address.
I had to set the “IP Address” property in the IIS Instance that served /exchange (and all the other Exchange web folders) to accept “(All Unassigned)”.
Apparently the intermittent errors were due to the server going Round-robin with all the available IP Addresses, and by allowing all IP addresses, the authentication errors were resolved.
Once this easy fix was made my Treo 700 connects perfectly all of the time! I no longer see the 85010014 or any other error. Now I heart my Treo 700w.