Unity3: Odd Performance drop due to non active script.

I have a script that loads an image from a web address onto a surface when the user clicks said surface. So, in an idle state, the script isn’t doing anything - theres an onGUI(), however it isn’t executing when the surface hasn’t been clicked and there isn’t even an Update() function defined.

Problem: When panning around the scene that contains a collection of such surfaces with the image downloaded script enabled (but no surface has been clicked), FPS drops by a factor of almost 2 - even though the script isn’t executing anything (or has any active coroutines). If I disable the script on the object, the FPS only drops by about 10% when panning around the scene. There is no performance drop when the camera is still.

There was no (0%) performance drop at all when running the same scene/scripts in unity 2.6 and panning/moving the camera.

Any ideas as to why this is observed? Any else notice phantom drops in performance when upgrading to 3.0?

Also, where can I download old versions of unity (2.6.1) If I want to reinstall 2.6.1 should this issue not be resolvable?