After updating to newest version I found an issue which I am not sure if related with resizing/thumbnails or simply procedural.
Just refined the testing and made following simple test case:
Withing images/stories/virtuemart/products I created subfolder called "MySubFolderA" and uploaded a picture by FTP "MyNewProductImage" into this directory. Now, when trying to link this image to a new product, it does not appear, is this a bug or am I doing something wrong?
If this should better be posted to another section, which would be the right one (Installation, Administration & Configuration, Product creation?)
See http://forum.virtuemart.net/index.php?topic=130713.msg450452#msg450452