It seems that for a gif to automatically loop you need to set some custom metadata for the file containing "NETSCAPE 2.0" for some reason. This probably dates back to looping gif's being first introduced in that very browser (GIF89a support).
So i was unable to actually fix my program. But luckily i found some code that works, using a different aproach to the problem (using MemoryStream and BinaryWriter).
The original code bit was found here, i haven't really done much in terms of changing anything. Just removing a reference to Response out and changing the delay time to something reasonable. Then i threw in the resizing bit from the last project.
So anyways, here are the code zipped as usual.
sharpGIFs 2.0.zip
And here are the final gif (same images as the post below, just looping this time around):