Ushio recommends using the probe start ballast for the 250w 10000k light though.... it really doesnt make sense. both the 175 and the 400w use pulse start. Even Hellolights.com shows the 250w ushio with the probe start (M58-H37)
http://www.hellolights.com/25unmagm58ba.html
do you know why this is or is it ok to use the pulse start for the 250w 10000k ushio?