RacerX: I would go with Brett's recommendation - check the crown to see if there are any dings, etc., that could impede accuracy. I would then check your bore for any visual obstructions and also check your chamber mouths for the same, dings or visual obstructions.
Lapping a 22 lr barrel is pretty easy but for the specifics I would recommend you go down to Veral Smith's Forum down the forum list here at Graybeard's, as he has spoken to lapping 22 lr bores previously and the process has proven quite productive.
Your ammo may also be a culprit and as kynardsj asked, have you tried different brands of ammo??? HTH.