Bug or?

[Myalthasanalt]

I've been noticing this more and more, and I assure you I will have pics up for it soon, as it seems my mind flay's cast time slows down suddenly without a debuff. This happens both in instances/raids and even when just practicing my rotation in org.
My mind flays normal cast time is 2.3 seconds, and it jumps to 2.7 (quartz is my cast bar addon). I have a bar on quartz that shows my latency, so I don't think it's that.
Again, I will get some pictures up here in the next few, but I was wondering if anyone has encountered the same problem

[Denae]

It's working correctly. When you re-cast mindflay on the same target, it is the same as refreshing a DoT, so your channel time for the next MF will add the time remaining to the next damage tick from your previous MF (and tick 4 times for damage instead of 3).