World Interaction ability is taken after crafting?

Well, as the title says, when I join my server everything is fine. GroupManager works like a charm and all my plugins work.
But as soon as I craft something in my inventory it kind of bugs. I'm still OP and in my admin group. Even plugins still work, but I cannot break blocks (they reappear) or place blocks (they just disappear) anymore.

Any wise help?

Tried without any other plugins, just with GroupManager. Problem remains....

Srry for doing triple post;
I managed to fix it by redownloading the client. Apparently it works with a clean minecraft.jar, but not with mine, although I only had TooManyItems installed.

Please mark as resolved, I will now post this as bug in Leaky....

EDIT by Moderator: merged posts, please use the edit button instead of double posting.