Would appreciate any help with this one..

Whenever I open up iPhoto ('09) for the last several weeks, it always imports the same photo (from Nov '09). Just this one photo, but it doesn't matter whether my iPhone is connected, a camera or even if I open iPhoto on its own...every single time, this one photo is always imported without any prompting on my part.
I sometimes get a message that says
"A photo has been found in the iPhoto library that was not imported. Would you like to import it".

If I say "no", I get "The photo has been placed in the folder Users/ etc/etc/iPhoto Library recovered photos" ...but it still imports it to my main iPhoto library in any case!

I have about 50 copies of this photo in my iPhoto library now and goodness knows how many recovered photos files! I've tried deleting them all of course, but it still comes back again the next time iPhoto opens.

So, before this drives me completely crazy, I would be really grateful if anyone tell me what's going on and how I fix it? Thanks!!