I recently switched to Avast and upon my first scan it discovered the W32:Trojan-gen within scenichp.exe. I put the file in the chest and removed it from the system. Question, before switching I used NAV for a number of years and was using the latest 2006 version. I also performed some online webscans and none were able to detect this trojan. Are the antivirus databases of each application that different from one another? Symantec doesn’t even list W32:Trojan-gan as a threat.
Yes, the virus databases of various antiviruses is different.
Trojan-gen is avast! name for a generic detection of various trojans, detecting tens of thousands of various malware (so, there’s no wonder symantec doesn’t know this name).
Welcome to the forums, kevinNJ, and to the Avast family! 
With a little time, I think you will realize how different and how much better it is to have Avast as your anti-virus solution. I am just a user like yourself but after having used avast for over 2 years, I can honestly say there is no better. Have I used the big name av services before? I can only say … been there, done that, won’t do it again.
Please come back often, learn more, and maybe help others.
Yes, it does look like I’m becoming a true believer. I’m sure I won’t go bacl to NSW and I gave up on McAfee longtime back.