Contacts Folder problem with e740

[Marco24]

Can anybody help ?
I've had an e740 for a few months now - no problems apart from the usual random Active Sync annoyances, but now my Contacts Folder has just stopped working. The PDA just beeps and does nothing when I tap the icon.
The Active Sync screen on the PC tells me that Contacts is synchronised, but I can no longer get in !
I've got plenty of memory left by the way.

[spursdude]

Do you use a task-manager to close your programs? If you closed contacts with a contact still open, it won't open back up. Have you tried a soft reset?

[Marco24]

No I don't use a task manager, unless a program hangs, but in any case the Contacts folder works fine on the PC, and even synchronises every time I change an entry within it.
In the meantime though, I've at least got my folder back on the PDA - I switched the lock on, and switched it back. The machine re-set and the folder worked again.
It would still be good to know WHY the problem happened, because I'm sure it'll happen again, but it looks like the urgent problem is resolved.
Thanks for your reply.