I mined several mines clean and then played the game for about 2 in game months went back to them to get some ore and the nodes were back but it wouldn't let me mine them.
The nodes themselfs are back and look exactly like the mineable ones, but I don't get the press A to mine the node. I have tryed all the mines that I have been to and all are the same.
Anyone have any ideas on how to fix this? Or am I doing something wrong? Everything I've read says they respawn in 30 in game days which it has been atleast 60 in game days.
If anyone else has had this problem please post so that I know that it isn't something that I'm missing.

i read the same thing from someone else, they said quitting the game and starting it again fixed it, hope this helps you... im still waiting for the orichalcum in bilegulch to respawn =/ Lydia needs some orcish armor =/

I'v had exactly the same problem, and iv tried restarting the game, and no luck, so hope it gets fixed in the upcoming patch