as carbon says, on the SDHC cards (which the DV can take) there is a number with a circle around it. If it doesnt have it, you probably are using an older version microSD pre-SDHC.
Mine arrived day before yesterday, but Ive only used it inside in low light. Works fine with no jumpiness with a class 4 SDHC Micro I nicked from my phone.
Dont bother with the CD that comes with the DV – it adds nothing and is mostly in chinese. The Engrish translation of the manual is a bit woeful too, but it's not a complicated thing to operate.
Looking forward to trying it out sometime properly. Can really fault it for the money.