Sync Folders with Orange UK 1.6 ROM?

[Guest ferret]

Inbox > Menu > Show Folders > Right Soft Key > Sync Folders.

Can someone please tell me what's it for, and everytime I press it I get "There is not enough memory to complete the operation".

I'm currently syncing Tasks, Calendar, Contacts and SmartPhoneNotes with Active Sync. Could it be that I'm not syncing the Inbox?

It happens if phone is on or off the cradle.

Thank you.