patience is wearing thin...Samsung I7500 switches off

phones been running well , no forced closes , good battery life ...
then over the last 2 days Ive had 2 instances when the phones just switched off!!!!

Only things Ive done differently are
1. performed a lot of application updates (either thru market , but mostly via aTrackDog (superb app btw))
2. added the Calendar widget to the RH desktop

ho hum, on both ocassions I needed to physically remove the battery to allow me to switch back on (long press on end call button)

Not impressed.
Im stuck on H6 firmware , I have always maintained I would try and upgrade officially via NPS software but if this continues I'll be doing it manually as I believe the later firmwares are better.

However as we all know , better the devil we know and H6 for me is in general pretty stable.

To Samsung : this phone is good but if all the bugs were ironed out and NPS was fixed fully this would be a class leader. missed opportunity.....