SD card was "TOO GOOD" for my new camera? Really?

My new camcorder is the Kodak Playfull (Ze1). The manual says to use a MINIMUM CL 4 card. So I got a SanDisk Cl 10 Extreme HD 8 GB. Fastest/best card at Best Buy. Well, the camera wigged out with this card, wouldn't recognize it, wouldn't format it. "Error". Brought it back to the store, guy says perhaps the card is "too good" for this tiny flip-style camera...better suited for a higher-end DSLR or pro-am camcorder. So I swapped it for a SanDisk 8GB Ultra, Cl 4. So far it's OK, and no errors. QUESTION: does this "too good a card" explanation sound fishy? I would think the most kick-a$$ card would perform the best. What do you think? Thanks.