We have had a few issues with Win7 and ePO 4, but haven't had to recreate tasks. We though this was going to happen because the 30 or so Win 7 systems in ePO 4 weren't updateing DATs, and I noticed they didn't have any of the managed tasks. But I believe this is related to the fact that we currently have ePO and VSE 8.7 patch 2 in the image for WIn7.
When we ran an agent fix tool we created (just a wise package that does a /forceunisntall and a /forceinstall on the agent file for the correct server) and had the systems check in, they got the tasks. I have noticed that the CMDAgent.exe won't run with UAC enabled though. Anyone noticed that, or know a way around it other than disabling UAC?
Although the KB66707 is for Vista, I believe the same applies for Windows 7 - need to run cmdagent from a command prompt with administrator privileges.
Just to confirm what Sailendra stated, if you enable the "Show the McAfee system tray icon (Windows only)" option and open the status monitor, you don't need the elevated priviledges. If you want to run cmdagent.exe from command prompt, it must be an admin command prompt. I also have startup scripts via AD group policy that launch cmdagent.exe that work fine in windows 7 x86/x64 using system credentials.