2nd gear grinding Fiesta Zetec 56 plate?

Hi i have a fiesta Zetec 1.25 56 plate and sometimes when i try to put it in 2nd gear it grinds and pops out, this happens like 10 or 15 times a day at least, all the other gears work fine its only when i try going into 2nd it grinds, what is the likely problem here? and yes i have my foot all the way on the clutch. lol.

Thanks in advance

Joe
October 2007