No problems. As mentioned I am pretty happy with the units. I was also at the Perth FPAA conference and saw Chris and the Bullex guys with the new laser unit. It has some really positive benefits from a Com. Ed. Dept. perspective - being able to run training actually within an office environment rather than as one organisation does, just show a cut away unit and a "talk and chalk". Today I used the Hotshot for evacuation drills in a factory. Set it up so that it had "flames" inside a large machine. It was very effective. The people actually thought the machine was on fire. Next step is to use it in conjunction with a smoke generator - much more realistic :-)