Can't imagine a theme would break that, but who knows - try updating a system back to the default theme and settings and see what happens. Also, he client files installed if you look in Program Files or are they missing, too?
Try un-hiding sys tray icons. If you right click your start button and go to properties you can put a check mark or uncheck the "hide inactive icons" in your sys tray.
It is possible that it is flagging this as an inactive icon. If you are hiding inactive icons, click the cusomize button to the right of the "hide inactive icons" check box in your properties and scroll down till you see the SB Tray manager. Set it to "always Show"
Christopher-Boston: yep, will try that with default theme. Client files are all there (and also "manager" in c:\Program Files\SafeBoot Tray Manager\SbTrayManager.exe).
ESB: actually I've read your thread but it seems it is not my case.
mwilke: that's not the case. Again I must say that SbTrayManager.exe is missing in Run key in the registry so it physically doesn't run on the machine. And I have no idea why is that? I believe that it should be added during the installation of Safeboot. However the installer doesn't produce any log file so I can't check if the key was created or not.
Well I can try to monitor the installation with sysinternal's regmon but I'm bit lazy though.
m.taylor: well I was also thinking about antivirus (VSE 8.7) which might block writing to registry but didn't find anything relevant in the vse on-access scan log. VSE was enabled during the install, that's for sure.