I recall, during the enhancement alpha/beta, one of the devs stating that all ability increase enhancements should stack.
When they didn't then, I bug-reported it.
Now, much later, this is still broken on the current Lama build. I have bug-reported it again.
However, I would think that having a bunch of enhancements simply NOT WORKING would be pretty high priority for getting fixed. I would love to get a "read by QA" on this issue, and would appreciate even more hearing that they are trying to fix this issue BEFORE the x-pack goes live. Thanks.