Yeah, whenever I try to upload, I will sometimes lose all connection the PMC for a little while. So, I really believe it is a problem on their end.
I really hope this gets fixed soon though, I deleted my texture pack file from my post to upload the new one, and since it hasn't let me upload, my post currently doesn't have a downloadable file :/
--EDIT--
I can just add a mediafire link on the post, but still. lol