2 new SDHC 16GB sandisk 4 cards, no problem on recording but in playback on both cards 2X message "media need resore". Also not possible to copy the file with that problem. Only sollution was with clipbrowser cut the clip in parts en create 2 new files. I lost only a few seconds of the recording material but I feel not happy with this problem. Anybody with the same problem?? Thanks

Yes, I had it once. I checked all my SDHC Sandisc cards with full writing/reading but must have overseen one error. Later I could record without error - but playback and copying to HDD was not possible.
I did the same - cutting in parts, loosing seconds. The card was defect, bad sectors, not repairable.