Very odd, do you use any unusual locale or have a character name with special characters (not that it should matter).
Nope.. Ive tested it with other chars and accounts and seems to work fine.
Combat started - my dps appears in black no matter what color settings i choose. Shaman one is recorded fine.
After aprox 20 seconds - my dps is completly gone, shaman one is still there.
Another kill - i start from 0 again, shaman dps still working fine.
Both me and shaman are using the latest Recount, freshly installed. Also he sees my dps in exacly the same way (black, disappearing after 20 seconds then starting for 0).
It happens the same in raid / party / pve / pvp etc.. Other warriors dps is recorded well. Likewise my other chars.
It doesnt record my own damage.
Works fine for my druid char by my warrior dps is showed in a black line that completly disappears after a few seconds of ooc. Same thing happens to the other Recount users in the party (they see my dps in black and only while in combat, then it my dps gets reseted to 0).
Installed and reinstalled, reseted profiles to defaults, copy settings from one profile to the other.. nothin worked so far.