Some STBs can be sensitive to positioning, but it is usually not too critical.
When MCE sends a channel command you should see 3 flashes from the RedEye LED in response to MCE, and you should see the STB's lower green LED flash immediately after each RedEye flash.
Proximity to the MCE IR box should not be a problem.
Email me at
mike@redremote.co.uk if you still have problems.