You've got an awesome paintball gun, but you notice your paintballs tend to lob or vear to the right or left.  Don't worry, it's probably not your new paintball gun.  First, make sure your barrel is clean - use a squeegee; they're cheap and easy to use.  If this doesn't work, try using a better grade of paintball.  For example, Karnage Paintballs make several grades; try the Karnage Rip Tournament Grade paintballs or the Karnage Premium Grade.  They cost a little more but they really are better; once you try them, going back to your old brand will frustrate you.  The AG1 from RAP4 are also a pretty good medium grade - not as expensive as tournament grades but much better than the paintballs you can buy at Wal-Mart.  You can also try upgrading your barrel.  Try a Tactical Rifled barrel or the Linear Rifled barrel (from Smart Parts).  Also, make sure your paintballs are stored in an even tempurature.  Sometimes they will fly different if they are too cold or too hot.  You might also consider adding an expansion chamber or a flexi-air buttstock.  These items provide a small chamber for the CO2 to enter and warm up a little before reaching the ball.  This allows for a more even temperature (and thus more even pressure) and your gun will fire more consistently.