I've been using Transcend 32GB class 10 card since I got the cam and have had absolutely no problems with it at all. Also use them in my 550D with the same results. Hope that helps...
I also use 16gb class 10 transcends, all my cards are transcend, they've been through hell and back with not failures. I trust them more than Sandisk and Lexar.
If you're shooting anything important, you should always have backups. Backup cards, a hard drive to back up footage to, etc.
The truth is all memory will fail. Buying from a reputable company will only go so far (Sandisk, Transcend, etc.). I've had a Sandisk card fail after just one day of use. It was a faulty card. Exchanged it for a new one and it still works to this day (5+ years later).
Transcend has a lifetime warranty AND a good track record for quality memory. I don't think getting Sandisk will improve your chances of a corrupted memory card.
If I had a card that was "glitchy" I would send it in immediately and get it exchanged for a new one. That's what the lifetime warranty with Transcend cards is for. Don't wait until it fails completely.
I've been using a 16GB Class 6 from Transcend with my GH2 and have had no problems at all. I also have two 8GB Class 10 cards but they're still in their packaging.
And I agree with Jive, send the card back at the first hint of a glitch.
I bought a sandisk 32gb class 10 for near £100 died on me within 2 months...I beg to differ.
With that I now use Transcend and verbatim...not wasting £££ on a overpriced sandisk again.
All SD cards can just die...so better to go for the best priced that works.
Simply shoot and backup asap on more than one media if possible!
I think it's just like with hard drives....once a person has a bad experience with a particular brand, you swear by another brand until IT fails you. I've stuck with Transcend Sandisk over the past several years for video and photo. I've never had a memory stick failure of any kind until I tried using Transcend in the GH1, which had write problems and one total and complete failure of the card almost immediately...it couldn't be re-formatted at all. Ever since, I've stuck with Sandisk in my video cams, and cheaper Transcends in my audio recorders...and crossing my fingers. I shoot about 40-50 weddings a year by myself, with 3 cameras and 3 digital audio recorders. So, about all you can do for live events is make sure you have a backup camera rolling. GH1's are so cheap now, you can have one for each hand shooting video, one hanging around your neck for photos, another in the balcony, and one watching your car out in the parking lot.