Underweight?

I think he looks fine. I would switch to larger prey though (small mice/rat pups). What I saw with some of my little ones is that they will some times put on length over girth. My male spider is long and thin but he won't put on girth, he actually refuses every now and again. They all grow different, one of my females seems to be against putting on length and is a little girthy.
My skinny spider:
http://i1139.photobucket.com/albums/...2/DSCN0592.jpg

Yeah, my spider does that too, seems to put on length more than girth! I cannot wait for him to shed so I know hes growing lol. He hasn't shed once since I have had h im and my female normal has shed twice since I have had her, which has been here about a month longer than him.

BTW, my breeder said here, take this and see if he will eat it *rat pup* and he eats ANYTHING lol, I don't think hes going to have a problem switching to rats as he ate that pup like nothing, but he doesn't have enough pups to supply ME and himself, so I am going to stick to small-medium mice then normal mice, until he can eat small rats, then I will officially switch him over. If my guy would just breed more rodents!!! lol