Class 6 SDHC cards,

That just comes down to the card, it just can't keep up with the constant speed that is needed to write the video.
The Panasonic SD-card also have this problem with the K7.

I said it's speed but it can also be the K7 that use a way to write data to the card which the card don't like, we will probably never know the cause.

Sandisk are proven to work perfectly and I believe Toshiba also but I don't know about the other cards, you can look at the Pentaxforums.com to see if they have more information.

Here is a topic link
Another one, this one is better link

Nathan - the Class number covers a range of speeds, not a single one. Current Extreme IIIs are 30mb/s. Early ones are slower although still badged as Extreme IIIs.

The ones before that where classed 20mb/s
There never was a class 10 officially in SD land, class 6 was the highest. But it seems they added a class 10 now.
http://en.wikipedia.org/wiki/Sd_card#SD_Speed_Class_Ratings

Every card that at least have minimum transfer rate of 6 MByte/s has already the highest class, class 6.
If you want you could call the older extreme III class 20 cards and the newer Class 30.

WARNING


This poster has 2 posts to his name - both made by bumping old threads and both selling his stuff

Yep he's still here it seems .

Poster now banned.

Thanks John - I was fooled by his bumping the last time hence my comment