From a thread at AVSforum:
[I]RC1 indicates that the recorder is set for operating code "1." If the remote does not control the recorder it needs to be reset to code 1. Hold down the remote's "1" button and hold down the ENTER button at the same time for several seconds. The remote will be reset to code "1." The other codes (2 and 3) are reset in the same way.
To reset the recorder to another code one enters the setup menu to do that. After resetting the recorder's code the remote is reset as stated above.
This information is found in the DMR-EZ28 Operating Instructions on page 48.[/I]