“Tropic Thunder” keeps slowly inching closer and closer to looking funny. If anyone’s been keeping score, we’ve been pretty wary of this thing as it only looks marginally funny at times and Ben Stiller’s hammy mugging is usually insufferable. This trailer is more of the same, but with new clips and less Stiller, so maybe that’s why we’re cautiously optimistic about it, but we just got burned last weekend with “optimism,” so we won’t be letting our guard down. The soundtrack comes out August 5, btw and garage rockers The Mooney Suzuki make a cameo in the film.