Though avast is normally able to remove infected restore points and the only reason it can't is as I said before it can't extract a file from with in an installation archive (the A0003837.msi which is the actual restore point file).
The virus isn't continuing to establish itself in the System Volume Information folder (it is a protected area) and the restore point is the same identity number as it the file that comprises the restore point, A0003837.msi is this was recreated, both of these would be different. I believe it is simply because you didn't clear the restore points or the action failed.
You don't have to be in safe mode to create a clean restore point.
I don't know the steps you took or if you followed the info on FWF's links so I will reproduce the steps again.
Create Clean Restore Point - Clear old Restore Points.
To create a clean System Restore point:
1. Click Start, All Programs, Accessories, System tools, System Restore.
2. In the pop-up that appears fill in the radio button to Create a Restore Point
3. Click NEXT
4. Enter a useful name that you will remember if you need to find this again (Clean Restore Point)
5. Click CREATE
You now have a clean restore point, you should clear the old ones:
1. Click Start, All Programs, Accessories, System tools, Disk Clean Up
2. Click OK on the C: drive
3. Click the More Options tab
4. In the System Restore section click the Clean Up button