you're probably due for a new clutch.. i'd say.. and while they're/you're in there, replace the slave/TOB at the same time. I've never done a clutch on an Xterra before, so I don't know if the slave/throw out are internal or external.. but it's best to replace it anyway with the clutch. that's probably your problem, but without seeing it myself I cant say definatly- but it really does sound like that's it. goodluck,

Sarah

PS-Xtra_blue.. good job :p