Install and restart in Firefox

It is interesting to see that Firefox suffers the same problems that MS-Windows does. Every time an extension is installed it says it is necessary to restart before changes will take effect. Why can't they apply on the fly like most GNU-Linux desktop applications?

What is worse that Firefox's offer to Restart doesn't actually work, I installed Filterset.G Updater on the latest 2.0.0.11 (what's with the silly numbering?) and clicked "Restart" when it offered, and when it restarted it hadn't really restarted, as Filterset.G hadn't run its first-run functions to download the advert block list! I had to close it, and manually restart to get it to download the advert block list.

..so come on Firefox developers, catch up!