Can JPGs be messed up in transfer from SD card to computer?

I'm not sure if this is the right forum for this topic, but feel free to move it if it's not.

I have a four-year-old Panasonic Lumix camera - takes great pictures, never given me a problem - and a weird thing happened today. I took 88 pictures at a parade and about a third of them had these weird colored bars on them, like this:

So I thought I had a bad image sensor - goodbye camera! - but I noticed that the thumbnails for my pictures were perfect in Windows 7. It was just the full-blown photo that was bad.

Went back to my memory card and used PC Inspector File Recovery and darned if all my pictures weren't perfect! It took a while - PCIFR kept crashing - but I restored all 88 photos from the card and all's well and good.

Here's the same photo as I recovered it:

What might have happened here? Is it possible for the card to not be seated right in the reader, or reader not seated right in the USB port, and the transfer murks the files up like this? Again, about a third of my 88 pictures were bad.

Ivan the SoSo said:

Have you tried to re-transfer the pics to see if the problem repeats?

I usually xfer using cut/paste off the card, so I had to "rescue" the photos using PC Inspector File recovery, which restores them to a different area (in this case, my HD of my computer).

I then reformatted my card, just in case. I'll probably shoot some "who cares" pictures just to see what happens regarding a transfer.

noobvious said:

I copy and paste, as opposed to cut and paste....so that the original is still there on the card, just in case.

Yeah - lesson learned here people - lesson learned!