Win32 Trojan Dropper Delf

On running Ad-Aware, it found this trojan and then claimed to have removed it after being told to do so.  I then re-booted and ran Norton 2009, which reported having removed all threats.  I then re-ran Ad-Aware and it found the same trojan still there.  I can’t find a reference to a trojan with this exact name in the Norton threat finder, but I feel there must be some malware present in my PC for Ad-Aware to make this report.  Ad-Aware support is no help!  Does anyone have any suggestions?