Thanks for all the answers everyone. I had it in the back of my mind that the problem may have been related to embeded newlines, but tried embedding my own in the header search strings, and just didn't get the combination quite right. The tr/// suggestion was helpful.

But I particularly like the fact that I can pass a regexp in. As I thought the issue over I actually thought to myself, "I wish I could just pass in a regexp." Viola, I can. ;)

Thanks again.