trojan in download?

Hello.I’m new to the forum.I have xp sp3,& my subscription to Webroot expires in a few days,so i decided to try Avast.I uninstalled Webroot first,since i also have Microsoft Security Essentials.
After i do a scan with Avast,MSE pops up saying that it caught a trojan(win32/Bumat!rts).It is located in…c:\Windows\Temp_Avast_\unp62498484.tmp
I tried a few times & the same thing happens(with different numbers after unp…tmp).
Is this a real trojan,or is MSE just reading it wrong.

Also,Avast says that the definition updates folder for MSE is suspicious.
I hope someone can help me.I really like this program,& want to keep it.Thank you in advance.

Well when you install multiple AV progams on one computer it can/will create all kind of mysterious windows errors and False Positive detections

Never install two antivirus (see reply from quietman7)
http://www.bleepingcomputer.com/forums/index.php?s=7c8217673a726b92cfc91ecfd4294a29&showtopic=260844&view=findpost&p=1441638