I think this was probably a website issue, relating mainly to certain instances where the virtual memory demanded by the scripts doing all the tasks simply exceed the limit. I am aware of this and will implement a solution if I can find one. I've also noticed times where the web simply seems bogged down - I had a timed out connection twice yesterday whilst browsing the site (and the fact that it is physically hosted in the US can make it even worse). Unfortunately software is not perfect and calls for patience at times. You can always contact me for help.
On a practical level I have noticed that trying to upload multiple images simultaneously can be an issue sometimes. Try sticking to one image at a time, unless you don't have problems.
Bear in mind that the scripts keep running sometimes even though you close the browser window - or will at least process everything up until that point. Two of GetaPix's pics did appear later after he had closed the window.