Internet Worm Protection Siganture file update

Today I received an updated Internet Worm Protection Signature File Version 20100604.001

It shows Internet Worm Protection is monitoring 1207 signatures.

 

However the previous Internet Worm Protection Signature File Version: 20100513.001 showed

Internet Worm Protection is monitoring 1499 signatures

 

I know that sometimes the files decrease in the number of signatures because of things like similar sigs and such.

But isn't the drop from 1499 to 1207 rather significant??

 

Did others get a reduced number of signatures on the latest up date?