Unity 4.3.(3 & 4) every 30 frames GPU renderer spike (Unity bug?)

This happens both in development and publishing modes with and without the profiler. There is no memory leak; however the behavior is as such: The game runs smooth for the first 3 minutes then begins to degrade into choppy movement.

This is due to renderer spikes. There are two cameras. A 3D GUI camera and a scene camera. There are no image effects. The renderer jumps to 6ms from .2ms every 30 frames.

Our scripts are pretty optimized, variables cached etc. There is no clear correlation between script cpu calls and gpu spikes.

I have found similar questions posted and I am currently wondering if this is a Unity specific bug or some other issue.

There is an issue tracker for this http://issuetracker.unity3d.com/issues/rendertexture-dot-setactive-profiler-spikes Please up vote this severe issue!