Leave it to Microsoft to make it confusing: Right click the
Taskbar, choose Properties and I'll bet "Hide Inactive Icons" isn't
checked, right? Clear the checkbox, hit Apply, and you're in
business. And if your System tray is ever FUBAR, grab a copy of the
Taskbar Repair Tool. It's a miraculous freebie ($5 for the Pro
version) that fixes dozens (36 to be exact) of Taskbar, Quick
Launch, and Systray problems.