I've had my TyTn II for about 7 months now and yesterday it just started playing up. I made no software or hardware changes or did anything unusual. It just wouldn't go into standby, and when it did, it was a Standby Of Death (SOD). Also, when I slid the keyboard out, the screen wouldn't flip to horizontal.
I've checked about a bit for Windows Mobile 6.1 update for this device (T-mobile Vario III) and it's not released yet. Anyway, after many soft resets it seems to be playing nice again so I'll post again if it redevelops.
This was a useful post about it all: http://forum.xda-developers.com/archive/index.php/t-332088.html
So, I lived with this problem for a while and in the end bit the bullet and did a hard-reset. This worked and the keyboard is now behaving 🙂