Running FireFox 2 and 3 on the same machine

[Dave M G]

Ubuntu Users,

I like the new FireFox 3 that comes as the default browser on Ubuntu 
Hardy Heron.

However, I have some add ons that I need for work (Zend toolbar, Web 
Developer toolbar) that are not yet compatible with FireFox version 3.

I used Synaptic to download FireFox version 2, and I can run it.

However, even though I can run version 2, the add-ons that are not 
compatible with version 3 are now incompatible with version 2 as well. I 
suspect this has something to do with the fact that versions 2 and 3 are 
sharing some configuration or profile settings.

Can I get version 2 to be more independent from the version 3 settings?

Thank you for any advice.

-- 
Dave M G