Aiptek IS DV2

the camera does not come with a memory card. try buying one at walmart.

These cameras have a very small internal memory so that it doesn't take much to fill it up. You really need to buy a memory card to use them.

These cameras do not come with memory cards and have a very small internal memory. It doesn't take much to fill the memory with pictures and even less with video.

You need more space on your camera, or you need a SD memory card.

Seems like its time to flush the contents of the memory card of camcorder to a computer.
There's a limited amount of memory in every memory card. After constant recording, the memory  gets full and the recorded stuff needs to be either deleted or flushed (uploaded to a computer) to make room for newly recorded stuff.

Unless you have a blank memory card, your problem should be solved by the above mentioned idea.