Anyone else using predator/x1/x64?

Although I've fired off a support request to RP, I get stuttering in the x64 version (1.6.1) and do not with the bridged x86 version. Also, "other" hosts don't have this issue, it's just x1. Doesn't seem to matter how many instances, buffer, and I'm @ 44.1.

Anyone else getting anything like this?