NIS 2010 - Full System Scan - Difference in scan results

Updated to NIS 2010 on Wednesday, 3-24.

 

Yesterday I ran my first full system scan which took 1:19:19 minutes.  Today I ran it again; it took 14:13 minutes.

 

Yesterday's results:

 

Files & Directories:  1,368,810

Registry Entries:  377

Processes & Start-Up Items:  3,327

Network & Browser Items:  251

Other:  6

Trusted Files:  8,848

Skipped Files:  212

 

Today's results:

 

Files & Directories:  224,008

Registry Entries:  377

Processes & Start-Up Items:  3,374

Network & Browser Items:  185

Other: 6

Trusted Files:  1,776

Skipped Files:  129,470

 

I ran the full system scan again today because Malwarebytes caught 4 infected items - 3 registry keys and 1 files.  The infected items were listed as Adware.webHancer.

 

Before I ran the scan today, I deleted the cookies/internet temporary files (which I do normally do everyday anyway).

 

My question:  Is this normal for NIS 2010 in subsequent scans to scan less items and also takes less time to scan?   Or did something go wrong?   In NIS 2009, whenever I ran the full system scan, it normally took about 1 1/2 hours each time. 

 

 

Windows XP, SP3

NIS8

NIS 2010 as of 3-24-10