First, I went into the edit profile section and deleted my current picture. Then, I saved those changes and went back in, and changed it to a new picture. For some reason, though, the site instead restored my old profile picture. I've done this three times in a row now. Same results.

...This site is problematic.

What profile picture are you trying to change it to? I know this site has a cache to help with server load, some things can take 15 minutes to appear (but I don't know if it includes profile pictures).

At the moment I see a blue, green, pink and purple... haze...? Is that what you were trying to change it to, or is that your old one?

There are some profile pic issues going on for all of us. My situation is that sometimes my pic shows and other times it does not. So, right now, it is visible to me... but when I go back to my profile it might not show up at all.

If you are seeing an image and it is the wrong one, there are several things to try. One is to wait for the cache to pick it up as Keladryie mentioned. The next is to force your LOCAL cache to clear by pressing Ctrl+F5 (windows) or [command]+F5 (mac). If neither of these options fixes your issue, then the problem is probably part of the overall profile picture troubles that the site is experiencing.

@Keladryie: That's my old picture. I tried changing it again today, and no good results. I guess it's pretty much just the site, then. Le sigh.