Ford Focus transmission question?

I have a 2003 Ford Focus with a 5 speed manual transmission. When I try to shift into 1st or 3rd gear; the shifter feels like it is hitting something. The transmission doesn't grind. It drives without any other noise or problems. The shifter feels like it is hitting something and makes a little bit of a clank when it goes into gear. The noise is louder if I shift it harder. The noise is the same if I'm driving or parked with the engine off. Could this be as simple as one of the shift cables hitting something or is it something like a synchro? It doesn't happen in any of the other gears; only 1st and 3rd.