Mazda Forum - Mazda Enthusiast Forums - Mazda 3 3rd gear grinding

Hi, I just purchased my first Mazda 3, a 2006 sedan with the 2.0L and a 5 speed. Everything seems to have checked out, but 3rd gear seems to grind ever so slightly. Some looking around seems to imply this is a bit of a known issues with these transmissions, anything in particular to look for before going for a rebuild? I was thinking changing the tranny fluid to something synthetic, getting my motor mounts checked out, and someone suggested solid shift bushings. In the meantime I'll just go from 2->4, which this engine is more than torquey enough to do. Also, since this is my first Mazda 3, I don't know much about them. Are there any known issues that I should keep an eye out for? It has ~123,000 miles on it, with nothing obviously wrong with it so far. Thanks for any and all help, I'm really excited to get into this thing, it's fun to drive and seems to handle better than even my sisters Civic!