im not sure if this is of any relevance but i remember you suggesting we try and switch to cdma auto prl and i can't seem to get it to stick. it always reverts back to wcdma.
i found a thread about trying to get cdma to stick on sprint with the evo.
Developing CDMA Preferred Network permanent fix [Archive] - xda-developers
the last post might be helpful and might not be. here it is
"have you guys tried editing the build.prop file and changing the preferred/default network?
it should look something like:
ro.ril.def.preferred.network = 4
ro.telephony.default_network = 4"
edit: nvm seems you have it set to that already