How to unmix the taskbar icons for symilar apps?

I like the Windows 7 task bar the way it is. I want to have only large icons instead of a long tail of icons and text. So I don't need to unmix all the icons. But I run both Firefox and Aurora. For those who don't know, Aurora is the night build of the same Firefox. Windows, somehow detects them as the same thing, which they're not, and stacks the icons. Now I use the two browsers for different purposes and I would like to tell Windows 7 task bar: Aurora is something different, like Opera or Chrome and I would like it displayed as such. Could you help?

Nope. They are two portable apps. Each starting from its own folder. Each with its own different name on the window bar. Each with its own icon: one has a fox going around the blue Earth and the other has the sun rising over the dark / nightly Earth. As long as Aurora is from the same major version as Firefox they go together. Otherwise they split. Say Aurora related to Firefox 9 won't mix with either Firefox 8 or 10, but it will be stacked with Firefox 9. How does Windows mix them and how to un mix them is the issue here.

You are right! Wonderful! I had no idea there is an associated file Application.ini. And the contents is identical on both vendor and app name. Thank you.

I can confirm the two are the same when it comes to Vendor and App name. But, at the time they were not stacked as they are not in sync. Weird, but my night build is from version 9 and the Firefox stable is updated to the latest version which means 10. But I think I'll get to sync them in about two weeks or sooner.