Virus was detected but not again

Avast 4.8 detected a trojan few days ago named Win32:Rootkit-gen [Rtk] in the windows folder. The file name is meta4.exe . It has been stored inside the virus chest. When I try to scan it again inside the virus chest, it wasn’t detected anymore as a trojan but as a normal file. When I try to upload it in virustotal, only few virus scanners detect it. I tried searching in the net, and the results were that is a virus. According to the results, it was created by Super(c), movie/audio file converter. Is this really a virus or not?

http://images.rzpogi.multiply.com/image/2/photos/13/500x500/1/meta4_exe.JPG?et=vUV2LPo%2CxCOZoFZs93YHGg&nmid=91415453

http://images.rzpogi.multiply.com/image/2/photos/13/500x500/2/no%20detection.JPG?et=1hQMWdmUHW81nXboPZViyw&nmid=91415453

the detection was removed inlast VPS update… you can restore the file from chest…