You cannot force your end users to use specific browsers and versions. This will limit your user base. Every browser (IE, Firefox, Chrome etc.) does not interpret the pages, stylesheets, javascript etc. in the same way. Hence there is every chance that your application pages may be distorted or not functioning on a specific browser version.

The memory seetings and the base operating system versions also cause behavioral distortion on your application. There comes the combinations of OS, Browser and memory settings. That means, your application may work great on Linux-Firefox 3.* version combination, but may not work properly on MS Windows-Firefox 3.* combination.

If we really evaluate all such combinations, it looks mad; but if you need more audience, this step cannot be missed out.

Using advanced techniques and tools, we can test your application display and behaviour on more than 100 combinations of OS and Browsers. These tests will be automated and can be done in a shorter timeframe, using tools such as Gomez.

On a lighter note, my behavior has some differences - in front of the boss Vs in front of my peers Vs in front of my customers Vs in front of my spouse.

Moral: Behavior of humans and software will differ based on the environment in which they operate.