Pulse updates?

Few days ago I noticed very strange behavior. Every day Symantec states it detects about 25-45 thousands of new threats. Pulse Updates are going to land every 5-15 minutes but the streamset.dat file just grows from few to several kilobytes between full definition set updates. It looks very strange because just 2 months ago, this file was near from 150 to 800kb(or even larger) between definition-set updates.

 

That indicates 2 possible cases.

1. Symantec did change the style how they detect malware.

2. There is something wrong with update mechanism or update servers. 

 

You experience the same?