Pattern matching problem

I have a rather complex dial plan. So far it has all worked fine, but I have run into a problem with pattern matching an extension. As a test I have the following in the dial plan:

exten => **hint-abc-1234,1,Pickup(1234)

works fine, but:

exten => _**hint-abc-XXXX,1,Pickup(${EXTEN:11})

fails with a 404 not found error for the extension. I’m at a loss as other uses of pattern matching are all fine. One difference is this is the only use of pattern matching in the dial plan that has a “-” in it.

Any ideas? A bug? Illegal characters?

zaptel 1.2.6