As some of you may know, I did not have much luck with my first Quark 123^2 light. I assumed to much BEFORE contacting 4sevens for help and i had my rear end handed to me. Not going to happen again! So to bring you up to speed, I got my first 123^2 and it had bad flickering problems. I talked to cust service and it was replaced really fast. I got my replacement light today. SUCCESS!!! it worked perfectly. Thousands of 4sevens customers cant be wrong. Later in the day, I had it in my lap and it suddenly went to Turbo. I went from brand new CR123 primaries to AW RCR123s, to nearly-dead CR123 primaries. I cleaned the contact (where the batteries meet the head) and i tightened the switch in the tailcap with needlenose plyers. Nothing helped. I have the regular version. It is too late to contact 4sevens cust support, but I am hoping I can get seom responses, theories, or a "do this and it might work". please help Quark users!