What was the program that onecare have suggested you to remove?
If its a third party security application, please make sure that it is throughly uninstalled. Try to check, you might need to run a special tool to completely remove the application.
If youre sure no part of the application is still reisiding on the system.
Use this tool.
OneCare firewall repair tool
http://www.microsoft.com/downloads/details.aspx?FamilyID=7ee728a2-3c67-4a12-8d7e-954e86233206&DisplayLang=en
If that won't resolve the problem contact support.
How to reach support (FAQ) -
http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=2421771&SiteID=2