IMG
http://db.tt/B226RYdg
Make sure you have dm3_mapcycle.txt and dm3_maplist.txt in ...hl2mp/ folder.
- Remove same named files from inside ...hl2mp/cfg/ folder.
Recheck server cvar mapcyclefile typing only cvar without value.
If still you not get this work, and you have server OS Linux,
Linux maybe prevent SM read those files. Something about CHMOD setting.