Blocking + Tactics = No weapon procs?

[Urist]

If you're blocking, and you activate one of the tactical feats (Sunder, Cleave, etc.), weapon effects other than direct damage don't appear to proc. Performing the same tactical feats when not actively blocking, effects proc as expected.

Using: Sunder, Trip, Cleave; using both 1-hand (with and without shield) and TWF styles.
Proc'd: Screaming, Shocking Blow (from the Greater Bold Trinket)
No proc: Bodyfeeder, Vampirism

Is this known behaviour? Is it WAI? It smells like a bug to me...

[gamj]

It's probably using your shield to sunder, trip, etc.

[Urist]

It's probably using your shield to sunder, trip, etc.

Good theory, but I got the same results whether sword+board, just sword, or sword+sword.
It also proc'd my screaming mace's extra sonic damage. Though I'll have to check that one when wearing a shield as well...

Nope, the sonic damage applied even with a shield equipped.

The only thing I haven't tried is a two-hander.