OK, just this past weekend I had a major computer problem installing updated MB drivers. Long story short, it went horribly wrong and I had to reinstall XP again (I did NOT reformat my HD) and I went thru the process of reinstalling programs (to get my 'uninstall' info back mostly). Now I am totally back to where I was before the 'glitch'
Anyways, RO was one of the games I tried to play initially after reinstalling the operating system and drivers and I did get the stuttering effect. I watched my fps bounce from green to red every second or so. Stuttering was noticable but not horrible
But
two of the last things I did to get back to my previous computer state was to tweak my ingame settings in the NVIDIA Control Panel and to apply a Multi-Core CPU Hotfix from Microsoft (as XP without it doesn't fully support multi-core cpus). Now my RO is back to its normal non-stuttering state.
If it was a coincidence, or one or both of those last things I did that helped to alleviate my temporary stuttering in RO, I don't know. I do know that I had no stuttering problems before I screwed up my computer, then I had stuttering problems before I did those last two things, then it was gone again when I got my computer back to its 'original' state.