Another hit for Jason Jones and Jim Harrison!
"Think this is sorted now.
I needed to disable the "apply session timeout to non-browser clients" in the advanced form options for the web listener that was shared for OWA and ActiveSync. If you follow the built-in wizards, this option is disabled by default for any listener that is selected for ActiveSync use - that'll teach me!
Thanks to Jim Harrison for the pointers!
"You don't want the FBA timeout applied to EAS clients.
The folks in Exch, WM6 and ISA all agreed that a wide-open 30-minute timeout was good for battery life. If you close that sooner, the client has to re-authenticate." "
So there you go -- those wizards do bear magic!
For the complete thread, go here: