I am bringing this up because Railcraft is a fairly standard addition to Feed The Beast packs that also contain Thaumcraft.

The Tunnel Bore seems to have an issue with placing rails onto Cinnabar Ore and all types of Vis Crystal ores. While using the Tunnel Bore you have to constantly babysit it to make sure it doesn't get stuck (thus defeating the purpose). I am unsure if this occurs with Amber, more testing is required to find out.

The second thing is that it cannot pass fences that are under it (ie: running into an abandoned mineshaft). I am sure it is caused by the block height of the fence, and I am unsure if this is already known or not.

If you need more information please let me know.

If you can't place objects on TC ores, its TC's problem. The block itself controls this.

Ok then. You can place objects on the ores, its just the tunnel bore that has a problem with it.

Oh, I see what the issue is, I'm not checking solidity, just whether its a normal cube. I'll fix that.