Your comments

^that. It might also be lag, in which case you really need to check your internet connection. If it's fine, it may be server lag or server problems.

By the way, is there a black or brown screen when your graphics "get stuck"? If yes, then check Problems and Solutions section in the forum, there'll probably be solutions.

Oh, and try using browsers or reinstalling client. Or Standalone Flash Player.

Hmm. Can you use another browser? Also, is the rest of the game working perfectly? If yes then lag can't be blamed either.

This really is a complicated issue, it might or might not have to do with the browser. Might be a browser bug. Can you shift to the version of Firefox you used before, or the one you have on your other computer?

First of all, there were problems with payment methods etc for this weekend. Secondly, if gift cards are not present there later today, then we players don't know if, and when, they will be available as payment method. If you can see them available later today, then consider the problem to be the payments issue for this weekend ;)

Hmm. You're unable to destroy or damage anyone, you can't pickup supplies? Try self-destructing. If it doesn't help, follow the instructions given above ;

Sometimes there's problems like unable to destroy, or pickup supplies. Just self-destruct or get yourself destroyed. It's a known bug in the game.

As for your other original problem, try playing from browsers. If that shows problems too, then I suppose it's a problem with your internet connection or your computer - better known as lag. OR with the server, like overcrowding, excessive chat, or other reasons that may cause server lag, as our very good unofficial helper sre123 has stated above.

EDIT: By the way, did you try this:

"it is advised to set the Internet Explorer cache to at least 500 megabytes." - from the helpsite link you linked in the original post?