My old Pace box was never 100%, but the new silver Samsung V box I've got now works fine with the standard IR blasters. I can't remember the last time it didn't change channel properly. It also seems quite forgiving with where the blaster is positioned, which the Pace was not.
MCE2005 (Reluctantly decided not to upgrade to TV Pack - will see if 7MC fixes the issues) | AMD64X2 3600+ | 1Gb Ram | 3x500Gb SATA | Hauppauge PVR150 | nVidia 7300LE silent GPU | Pig ugly big black case | Virgin Media cable | Xbox 360 wired extender