I just went though that myself
today.
I read and followed Sombre's advice to Honeybadger in Honeybadgers' Aksum thread.
What you have to do (from a near-total idiots understanding) is convert your sprites to a JPEG format, upload them to Free Image Hosting.com, copy the address and paste it in the "manage attachments" part below this section of the reply.
How did I do?? Did it once, two hours ago and already I'm an expert!!!!!!!
