I know Windows 7 is not officially supported, but I installed Bitdefender Total Security 2009 on a Windows 7 (build 7057 32bit).
I encountered only one major issue - when resuming the laptop from sleep, no networks connections are available, and the only way to fix this is via a reboot. I thought it was a driver/power management issue, but after countless tests, it just wouldn't work until I uninstalled Bitdefender. Note that I tried just disabling the firewall but it wasn't enough.
If you need any details of this issue, I'll be happy to provide.