The order of things RR is doing on resume is:
WinAMP Open Playlist (Winamp.m3u)
RR Reload of playlist
RR Reload Resume.INI
RR Reopen Open COM Ports
RR Restore Shuffle&Repeat Mode
I'd suggest save your HORM save point with winamp STOPPED. This should allow RR to resume propperly when using HORM, because the Reload Resume.INI function does absolutely nothing if winamp is currently playing (and that's where the song number/position is set for resume playing)..