Yes I used a digital probe directly on the basking spot... just for fun, I changed it out with my regular 75 watt basking bulb and that with the probe reached 107degrees. I don't get it. Maybe it's a bad bulb, things happen... I am just going to switch it out with my 150watt basking bulb with a dimmer and use a 36'' halogen with that... just thought I'd ask! I'm not familiar with the MVBs. Thanks for all your help, it's greatly appreciated! And by the way... does anyone think a 4 month old beardie that is 13 inches sound unusual? He is growing extremely fast!! Thanks!