Try changing that to ALL. If you're getting the same pointValue coming through multiple times and it changes then stays the same after 6 seconds, there's a chance it may not fire due to the fact the last value is the same as the current value. You can always put an if statement in your meta point code to verify it's a valid alert.
EDIT: one more thing, what's the delay on your event alarm? How long does it need to stay a certain value before it fires?
EDIT 2: I learned when utilising the API that I need to ensure I have enough cached values in order to ensure all metapoint scripts would fire. I'd suggest making your default cache for your input point used in your meta script to have at least 10-20 for a value. This will ensure all value updates are cached and so nothing is lost..