Missing SysTray Icon

I have noticed that, when running some other real-time protection tools, the NOD32 system tray icon does not appear.

Case in point..

I downloaded the free version of Ewido. Well, it comes with a 14 day trial use of the real-time protection(RT) and auto-update(AU). Well for the entire 2 weeks of allowing it to run the RT and AU, NOD32 started up and ran like normal, except with no icon.
As soon as the trial period expired and Ewido just became On-Demand, The icon started appearing again.

I always checked the task-manager and sure enough, it was running. If I went into to the start | program | Eset and launched the Control Console, it appeared, but upon restart, it did it again.

I thought this might be of use to those that have run into similar problems.

Anybody know why this anomoly might occur?