Rogue Poison Skill is Capped and Can't be Trained Higher

[parkerbrom 0]

My level 28 undead rogue on the PVE server has a poison skill that is capped at 140/140 and i can't seem to train it any higher. Am I missing something that needs to be done to progress it further or is this just a bug?

Thanks

[Sammis 1]

Poisons skill is 5 point per your character level.