photo importing problems :(

[se44@hotmail.co]

hi, i've never had a problem with importing photos before, but today when i tried to import some photos from my camera i got the message
*"The following files could not be imported (they may be an unrecognized file type or the files may not contain valid data)"*
however, some photos are imported and have thumbnails i can see and can open (they sometimes work on iphoto and not image capture, or vise versa), others dont have thumbnails but i can open them, and some just wont import at all. (all photos are jpegs)

i tried importing using image capture but had the same problem and got the error message
*"Couldn’t open the file. It may be corrupt or a file format that Preview doesn’t recognize."*

as i said, ive never had this problem before and i dont think ive changed any settings or anything.
a difference ive seen is in the photo info..the ones that work show the camera model etc, but the ones which dont work dont show this.

basically i need help as ive searched the net looking for a solution and im stuck! any help is appreciated!

thanks!