I have the same problem w/ my canon ixus 100IS.UNIDENTIFIED IMaGE

Here is a link to the page of your owner's manual that explains that. You can download the manual here too if you've misplaced it: http://www.retrevo.com/pdf/23931ci674/9/Embedding+the+Date+in+the+Image+Data#q=Canon+80+IS

Simple...get yourself a card reader and use it from now on.

iPhoto is for still pictures. iMovie is for videos. Use a card reader to download your videos to a folder you create on your desktop. From there, you can import to iMovie or just play them using Quicktime.

Try formatting the memory card (or changing it). You probably have some bad sectors.

If this does not help, take the camera to a Canon dealer, it's probably a software problem

Lens errors are fairly common. Usually it's sand or grit interfering with the lens extension mechanism. Or the camera's been dropped with the lens extended. Or the camera has been powered on, but the lens had been blocked preventing its extension. Or the battery ran down with the lens extended ... Unfortunately, many cameras that fall prey to this can only be corrected by professional repair. But, here are some things that you can do that may correct it. They only seem to work for less than 40% of the lens errors, but if the camera is out of warranty, they're worth a try:

if it is insured you could take it to a camra shop and get a free estimate and go from there.

Use a card reader to download them to a folder you create on your desktop.

Try using a separate card reader to download your videos to a folder you create on your desktop.

You think you can try photo recovery software to see if you can rescue the lost photos or movies, here are some you may rely on. Both programs can also recover videos and music.

Photo Recovery Software (for Windows)
Mac Photo Recovery Software (for Mac OS X)

Be careful: Before your pictures and videos are recovered, do not attempt to save more files to the memory card in case the original files(your pictures) are overwritten.

I have the same problem with my Canon Powershot SX110IS. images dissapear with the notation "unidentified image". I brought my camera in to a local camera shop, and they were able to save the lost images. They told me I had an inexpensive, low quality memory card that is causing this problem. I upgraded to a high quality one and haven't had the problem since.