ci breaks links unnecessarily & when it says file is unchanged

Have file w/a hardlinked copy:

>  ll -i dedup dedupl
3892399866 -rwxr-x--x 2 86354 May 13 13:12 dedup*
3892399866 -rwxr-x--x 2 86354 May 13 13:12 dedupl*

Do 'ci':
>  ci dedup
RCS/dedup,v  <--  dedup
file is unchanged; reverting to previous revision 1.47
done

Hardlinks are broken:
>  ll -i dedup dedupl
3892399867 -rwxr-x--x 1 86354 May 13 13:15 dedup*
3892399866 -rwxr-x--x 1 86354 May 13 13:12 dedupl*

1) Why are hardlinks _ever_ broken on checking a file in?
2) especially in in the case when it says "file is unchanged"

tnx...