Exchange ActiveSync Probs

[Guest gumption]

Hi. I'm trying to select individual inbox folders to synchronize my C500 with our Exchange 2003 server. Synchronization is working fine, but when I try and add inbox folders in Activesync (Options->Configure->Inbox->Settings->Select Folders), it keeps coming up with "Before you can select additional e-mail folders for synchronization, you must first connect your mobile device to this computer and synchronize Inbox information"

The C500 *is* connected and synchronized. Is it not possible to synchronize other mail folders when connecting to Exchange rather than Outlook? I can view all my folders if I synchronize with Outlook.