Rob, what speed is your 8Gb micro-SD? If it has a symbol like a capital C with a number inside (eg. C 2, 4 or 6) that's its speed rating. Eg. top right of this one:
Reason I ask is that from my research on the net it seems you need a high speed card (class 6) to allow the camera to dump stuff out without glitches.
I've tried a 4Gb class 2 and an 8Gb class 4 in mine, both give slightly jerky video outdoors, but seem to be perfectly smooth in lower light indoors even with my class 2 card, almost as if the camera's having trouble recording all the detail it picks up in full daylight. Seems to be that when mine's dropping frames the date/time flickers on the played back video.
I've ordered a 4Gb class 6 card to try.