Spitalfield have announced that the reason they dropped off the remaining Warped Tour dates is because their guitarist left the band:

The reason we had to miss the last ten dates of Warped Tour is because we unexpectedly received word from our guitar player that he would no longer be touring with the band come this fall. Our new record, "Better Than Knowing Where You Are", is slated for an October 3rd release- and we were forced to face the choice of losing Dan Lowder right when the record comes out (and dealing with it then) - or canceling a string of shows to get home and begin rehearsing with a fill-in guitar player to be full strength when the record comes out.

Lowder was a member of the band since 2000 and is leaving due to personal reasons.