angryoptimist

Same thing happening with me. I set up a clean 1.3.2 jar with Forge build #247, no mods and tested redstone wire (in both on-and-off state), (regular and redstone) torches, both doors, repeaters, and both pressure plates. All of these were place-able and stayed placed on all types of upside-down staircases (stone/rock-type or wood-type) and also worked on top slabs of the cobblestone, stone, stone brick, brick, and sandstone varieties--but none of these things could be placed on oak, spruce, birch, or jungle wooden top slabs. I've attached a screenshot--mostly because I went to the trouble of taking it, so I may as well. I've also attached a log file--for all the good that may do. Doesn't look like anything relating to this is in there. I've tested this on Ubuntu 12.something as well as Debian Sid (very up-to-date). Don't have Windows to test it on, but that really shouldn't matter--if it's not the same result, that'd be incredibly weird. Tested on both the Java 6/7 varieties, if that makes a difference (log is from running 7 variety; java -version reports "1.7.0_03"). Also tested less extensively a little while ago on an earlier build of Forge for 1.3.2 (#241? I can't remember), where I found I couldn't place torches on sandstone top slabs. Hope this helps. EDIT: Oh, and I tested minecart track, because why not. Forgot about that until I looked at my own screenshot. I tested the pressure plates in another world (started the one in the screenshot just for that purpose and apparently forgot about them).