wierd wrong image appearing

Hi

I've encountered a problem with a image, I'm using ckfinder and I've uploaded some large images around 1000px wide.
Now I've cropped (400px wide ) the same image and deleted the previous image and uploaded the cropped image all in ckfinder using the same file name.
The image appears cropped in the thumnails, but when i insert the image, the old image (1000px) appears, Note it's not being scaled.
All the paths appear fine and point to the correct directories but i can't work out how this is happening.

I've now renamed the image and then the correct image shows up, so using a deleted image name seems to somehow call up the old image, eventhough I can't see it on the server. Is it a server issue ?

Originally I done a few uploads with fckeditor, but the userfiles for this is empty.

Any ideas anyone ?

thanks