Well I had a same problem with XRC. There can be various reasons which can cause. Here are some of the tips if you want to try.
1) Try disabling Anti-sticking option in ARCEND Condition file, if you are using one.
2) Try play with voltage and current setting in your arc condition file. According to me you want to try reducing some voltage and increasing current.
3) Try to teach your weld points little bit away from your work-piece, allowing more stick-out.
4) If you are using reamer make sure reamer blades are sharp enough to remove spatter and anti-spatter spray works properly.