Sorry I dropped the thread.
Code 460 means the meter has just rebooted and is resuming logging. Seeing it at the start of a log might not be a problem – if you reset the meter or took the batteries out I’d expect to see the 460 code. If it’s being generated spontaneously, that means the meter is rebooting. It would make me suspect the batteries.
Regarding SD card types: I haven’t had problems with anything from Sandisk or Kingston. I’ve also used the Samsung 32GB cards with success. The only cards that have personally given me trouble turned out to be ebay counterfeits.
I made a bulk purchase of 128MB SD cards a while ago and have a bunch of them around, they haven’t given me any trouble and I’d happily send you a few. Email me if you’re interested in that. I’m out of town but can send them when I return (Wednesday).
Sorry for the trouble, best