What steps will reproduce the problem?
1. Have a level 85 feral druid with the 2 points in the Stampede talent (3rd tier)
2. Be in kitty form and feral charge a training dummy
3. Hit the Ravage spell (which will actually be the "Ravage!" spell or 81170 per Wowhead).

What is the expected output? What do you see instead?
What is see is game lag that seems to be about half of a second. If I disable Ovale it goes away.

Even if I completely remove all code from my script that has anything to do with Ravage and Stampede it happens (including removing the defines). I also see this if I use the default feral script, although the period of lag seems shorter - which may be due to my script being more complex than the default feral script. There is no other spell cast I am aware of that causes this. I am guessing it has something to do with the code that listens to the combat log - but I don't know why casting Ravage (technically Ravage!) which removes the Stampede buff  (81022) causes a slow down in the Ovale code. I did use the addon Eavesdrop to look at the Stampede buff - and I am seeing it come on and then fade properly when I feral charge and a few seconds later hit Ravage, and I just reconfirmed that I do not see the game lag when I disable Ovale.

What version of the product are you using?
4.2 but this problem was also in 4.1. It was first reported to me on August 11th in this post: http://fluiddruid.net/forum/viewtopic.php?p=4793#p4793

Do you have an error log of what happened?
No errors show up - just game lag - the entire screen freezes for a moment.

Please provide any additional information below.