[SID: 55000] IRC Identification Signature attack detected but not blocked.

For some reason when I receive the IPS alert as seen below, it's not blocking the traffic. I searched and found an identical posted article but it contained so solution. After opening IPS policy, I opened the Exceptions to see what rule 55000 was set for by default. It shows it as Block and Log. So why is the logged alert showing it as detect only?

Version: 12.1.2015.2015

[SID: 55000] IRC Identification Signature attack detected but not blocked. Application path: \DEVICE\HARDDISKVOLUME1\WINDOWS\SYSTEM32\MACROMED\FLASH\FLASHPLAYERPLUGIN_12_0_0_77.EXE