Even though ThermalTake says the FC-PGA Golden Orb will work with both Celeron I (PPGA) and Celeron II/Coppermine (FC-PGA, I am 0 for 2 on using it one the PPGA package. In both cases I have ended up with cracked sockets on the converter. I will not try it again.
Have you lapped your CPU? I've never tried a Golden Orb on a non-lapped PPGA Celeron, but it worked fine on my lapped C400. Eventually I lapped both Celeron and Orb, & it worked perfectly. Granted, I ruined one Slocket in the process of figuring it out, but it eventually worked fine. Also try bending the clips & using thermal paste (I'm assuming you are already, right?). The thermal paste will work as a lubrication, & bending the clips might just give you enough play to lock it in place. My Golden Orb ran my C400 perfectly at 575, so it was definitely worth it for me.