I have not run into an issue before with the Dynamic Suite causing a system wide slow down after running a virus scan.
I would check the virus scan logs and the system logs to see if there is anything there.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.