I bought an old copy of Sonar 8.0 Producer off of ebay for cheap, go to install it on my XP system, and then AVG pops up and says "Treat detected"

File name:  C:\DOCUMENTS AND SETTING\<my user profile>\LOCAL SETTINGS\TEMP\IS-PNN2E.TMP\CAKEWALK\DREAM\SETUPDSDXI2.EXE
Threat name:  IDP.Virus.A8320BFF
Severety level:  [4 red bars]
Category:  Virus
Description:  This is a known piece of Malware (malicious software).  It is recommended that you quarantine this threat.

Out of curiosity, I tried the installation on my Windows 7 64-bit laptop, also with AVG installed, and it didn't throw any flags.  So I tried looking this up here and on Google in general and found no info that specifically relates to Sonar, Dreamstation, the .exe file, or the "virus" name.  However, I did find that there is a "Virus TI" synth of some sort.  I went ahead an vaulted the file for now for fear that I bought some illicit copy that the seller created with "special plugins" of their own.

Has anyone heard of this or experienced this themselves?

Does this appear to be a new, unopened Sonar8?

If it has been registered, the license is not transferable, as you should know.
If it has not been registered, you are probably ok.
A legit copy will immediately prompt you to register it. If so, you have 30 days to provide it with a valid registration code before it shuts  down.
If it does not, you most likely have a hacked copy. If that's the case, it's anybody's guess as to what bonuses it came with.

Sounds like you've could have been dupped. That's most likely a pirated version as Sonar 8 has been off the shelves for a long time. You really can't buy it anymore. If it's not in the box then I'd toss it out.  Unless it's second hand ( not allowed ) and includes the complete package, the serial and was never registered. 

Why would you be worried about a virus in a legitimate copy of software on a disk? 

If you a genuine version you are probably getting a false positive however given the age of the program is this likely?

Unless it came in a sealed box you should proceed with great caution. Best case scenario its a real copy that has already been registered and you won't be able activate it, worse case its a hack will deposit a nasty payload on you PC.

If you do get it registered remember to get the 8.3.1 update which had a lot of new features and bug fixes. It's still available on the Cakewalk support site.

What was the reputation of the E bay seller? That used to be important. I'm not sure if E bay has gone bad but in the past you had to built up a reputation count, I have over 100 sales with no complaints as an example. That means I will also gladly take your item back if not satisfied. 
But somehow I get a feeling it's just a plain old used copy that you will have trouble as it might be registered already. The seller would have had to include that number which is not allowed. 

That's just the installation program for the Dreamstation DXi which is old anyway. I'd let it quarantine it and see what happens from there. 

Thanks for all the responses.  The ebay seller had a really high rating and the DVD/packaging all appeared to be genuine, so either it was repackaged used version or a really nice looking knockoff.  I'll proceed with caution.  Only reason I bought it was because I've been using Home Studio 6 for a long time and wanted to upgrade without shelling out for the latest and greatest X1 or X2 or whatever... thought a couple year old version for a lot less would be a good compromise 

AVG is not my favorite AV program. It could be wrong. 

It's probably legit.  There seems to be a lot of unsold copies of Sonar 8.0 in music stores.