Is anyone else having problems with "fastbreaking"? When breaking most, if not all, strands of redstones and coal I find, I get the message that fastbreaking was detected and that I need to wait 10 more seconds before breaking any more blocks. And it is really starting to make mining unbearable...

Is it just my internet?

I have had this problem before you need to re-install your minecraft.jar and delete your texture packs folder at the same time.

You do not need to delete you MC folder or your texture packs. It is Anti-Cheat, it needs to be tweaked a little which if you post on the Anit-Cheat Bug Report forums they'll look into it

this will do nothing but wast your time the server has a plugin that detects this stuff but it has not been nerffed yet so please don't delete your mc folder lol