I've seen no LiveUpdate or documentation on this bug, but apparently it's affecting other PCAnywhere Vista users as well. Rather than wait for Symantec to come up with a fix, I figured out that the rendering engine, Winawe32.exe is causing the problem.
- Right-click on your taskbar and select Task Manager.
- Select the Processes tab.
- Highlight Winawe32.exe and click End Process.
- When warned, click Okay.
- Close PCAnywhere.
- Reopen PCAnywhere and you should see all of your Remotes now.
Would be nice if Symantec fixed this bug with PCAnywhere, it's a real pain.