Neither did I until 3.12 was released. Now I get an unresponsive system for 5-10 minutes when the first update happens after the OS starts. It's not like it has to even be a large update. I can restart my system immediately after the database has updated and it will still lock me out while it has to do whatever it has to do with that giant database. So it obviously hasn't had enough time to get many updated definitions. (if any)
And it's not like my system is lacking resources either.
AMD Athlon 64 X2 Dual Core 4200+ 2.2GHz
2GB RAM
222GB free disk space...
(Running XP Pro SP2)
That's strange, it doesn't happen to me. When I first boot up,everything is normal and I might get the popup saying the database is being updated 2 or 3 times, but it never causes any slowdowns at all. I can browse, check mail, or do anything else I want. My system specs are way below yours too. I have XP SP3.