Antispyware – 1 (Adware.LinkMaker)

I have been experimenting with various antispyware products for some time now. I had Spybot-Search and Destroy and Ad-Aware installed. Besides those, there was the antispyware that comes along with ZoneAlarm. Then I tried SpyDefense beta. It showed a spyware called Adware.LinkMaker to be present on my system. After the scan, without removing the spyware I scanned using Ad-Aware, strangely it didn't show this spyware.