It's hard to beat this SanDisk 32GB Extreme Pro SDHC UHS-1 (although only the T3i can benefit from that currently)... Up to 90MB/s write speed... It's hard to imagine a 32GB card for $126.50!
Agreed i use 16GB Sandisk Extreme Pro's in both my 60D and 5D2.
Fantastic cards and have never skipped a beat shooting video, which is handy because the 60D gets mighty hot when shooting to the 29.59min mark.
OP the reason why your PNY card is playing up is because the Class X system is not clear cut.
This is why these cheap cars can pass at higher ratings than they can handle.
General rule of thumb is buy the fastest cards you can afford, from a reputable brand (but you can check eBay and similar, some camera place have genuine stock @ good prices on there sometimes - always check the reputation) and if shooting video instead of buying just 1x32GB buy 2x16GB instead, that way if you do have any issues with the card you don't loose ALL your footage.