Missing photos - Optio W60

I have an Optio W60, no problems until now.
Just returned from weeks holiday and plugged camera in to TV to look at photos. Shocked to find only photos from first day of holiday on camera. Had no suggestion of problems when using it during the week - seemed to take photos (and video clips) without any problems.
Memory card is an 8GB Transcend.
Not sure what to do. Is this a camera problem, or is this a memory card issue? Most importantly, are my photos likely to be hidden on the memory card somewhere, and can I retrieve them somehow?

Any suggestions appreciated.

There is plenty of free software on the web to reclaim lost images from your card.

Try to get the shots from the card before you take any more shots and risk overwriting the information. If that fails, sometimes formatting the card before recovery can work better.