Hi,
This error was caused by the new skill, not any xp differences between the two display names - there's actually a significant amount of xp leeway for RuneTrack display name changes (usually at least 500K xp, depending on the account and other factors). Essentially, your old name's stats did not include the dungeneering skill, while your new name's did. However, I've fixed the Name Change page to recognize the existence of a new skill.
After fixing the bug, I changed your RuneTrack display name by using the standard display name change page, and it all worked as it should.
