Yeah you can. You just gotta pop out like you're doing a nollie if I remember correctly (haven't played in a while) and work the left stick away from the ledge so you don't end up back on the ledge. Sorry if it doesn't make much sense.
Has anyone else ever gotten disc read errors on their ps3? It happened to me once before while playing skate to the point where nothing in the bluray drive would work (CDs, regular DVDs, etc) so I completely turned it off for a day or so, then turned it back on and it worked fine. Happened again last week and now it's a no go for what seems like forever. Googled around it seems like it's kind of a common problem that needs to be fixed by Sony.