When McAfee is doing updates & full scans I get no update or scan icon in the lower right corner of my windows task bar. Why is this?
That's because it updates silently. You can have it alert you if you wish.
Assuming 2010 product is installed.
Double-click the taskbar icon to open SecurityCenter
Click Navigation (top right)
Click general Settings & Alerts (mid-left)
Click Informational Alerts to expand that drawer
Check the item "Updates are Installed" and then click Apply.