Ok, this is ARRL# 151, listed in LOGic as 4J1. And it is listed here as deleted. So just go to tools/setup/list of valid values, locate DXCC 4J1, and mark it as deleted.
The ARRL actually lists this as R1MV.
http://www.arrl.org/file.../dxcclist_jan_2013a.txt
To change it, in tools/setup/list of valid values, click the CHANGE VALUE button, and enter R1MV. This will fix the log and DXCC list.
As for the prefix table, there is no need to have deleted entities in it. There is a record for it tho. Look for RI1M. Change the DXCC PFX to R1MV. What call do you have for your Malyj Vysotskij call?
Congrats on nearing Honor Roll!
73,
DH