xp only ver of comodo (2.4) asked to update to v3, then didn't

hey all, my mom uses the computer that i have comodo installed to, it asked her to update to v3, which she did but when it got to the point where it asked here to reboot the computer windows comes up saying that there is no firewall installed (i currently am downloading v3 manually from the website and have windows firewall enabled while i do so).

the updater it seems just uninstalled comodo 2.4 and not give me 3, why is that?

also is there any other things about v3 that i should know about?

I really want to use this on my vista laptop and forever ditch windows live onecare! But not until v3 is as solid a product as v2.4.