What happened to my skills?

[Artem1620]

I started out with 4 tumble, hide, move silently, and a few others. I gained a lvl (2) and turned them up 1, then i gained another lvl (3), turned them all up 1 again and they ended up being 9 instead of 7. What happened? i had a rouge btw. Is it class thing or what?

[mr_sir]

Skills also have modifiers that are affected by your stats and also some equipment has skill modifiers also. This may be the reason.