http://pastebin.com/u81heZ5u

after completing iron tank minecraft crashed cause a few tree leaves from forestry where nearby the tank see crashlog :/

english is not my best lang sry hope its enough :P

mfg

So...somehow you managed to get a block with the block id of a Tank and the TileEntity of a leaf.

I suspect that Forestry may not be properly cleaning tile entities when leaves are removed.

so its a problem from forestry right?

Most likely.