Quote Originally Posted by Suggestion View Post
Should i just move this thread to the bugs forum?
It's not a bug, your question has basically been ansered by Synestr in the 3rd post.

The amount of active debuffs on a mob is capped at 60, which can be reached pretty quickly in ST or with A/S ranks, especially when healers help dps'ing etc...

Shouldn't be an issue at all though if you do not let your DoT's fall off, since if you reapply your own DoT it overwrites the prior one and doesn't count as a new one.
Maybe it's an issue with your own rotation and your DoT's fall off from time to time? No offense, just an idea... ^^