Recently had a lamp out of a Mac 2K fixture. Had a blob on its globe one might expect came from someone touching the lamp. This lamp however had over 900 hours on it and was on tour so unlikely anyone had opened the fixture and touched the lamp since it had been installed. Also it's unlikely that such a blob/bubble on a lamp globe could surve that many hours without blowing. Turns out the lamp installed in the fixture right before this one was the first lamp ever installed in the fixture and it also had the very same problem, except that the blob on the globe exploded after 860 hours. If this bubble on the globe was not from touching the lamp, and there was a signifigant amount of time within the fixture it took to develop, what might be the causes of such a thing? I'll attempt to take and post a photo tomorrow.