Link image is not correct after submit

Hello there!

I have a weird problem i just can't seem to fix since i don't know where the problem lies.
The problem:
When i add a picture via a url it works just fine. But when i submit the image the image url is corrupted. The url is: http://mylink.com/%22http://mylink.com/ ... b2.JPG/%22 . Wich is obviously wrong...

Funny thing is that it is correct in phpmyadmin, so somewhere it just add's "http://mylink.com/%22". I just don't know where. It has worked properly last time i checked it (about 2-3 month's ago).
Thanks in advance!
Paul