@ThR: i mean that i install first the dr800sg-1.0-build1000 and the dr800sg-default-content again (i assume that's the standard software and/or basic software), after that i do update-dr800sg-verizon-0629. that way my device is working fine again.

it's very weird that it suddenly starts to act like a granny after an update. if i use the foregoing trick, it's ok again. i also mentioned that i've got another device, exactly the same and treated the same, and that one has absolutely no problems. i don't get that...