Jayflash, that's the exact combination of lights that I use (unfortunately the only 2 lights I have at the moment). However, I give my Inova X5t the new batteries and after 20 minutes of using the G2/P61, the virtually new batteries X5 batteries go into the G2. I like it when everything runs at full power.
Anyway, back on topic.
I have said this before in other threads, the outside larger spring on the lamp assembly must be shorter than the inside smaller spring for the bezel lockout. Different spring lengths result in different people's lamp assemblies requiring more or less turns to lockout.
Personally, I always have my G2 in my pocket, never it accidentally turned on. Therefore I rarely ever have to lockout.
Jeff