An alternative solution to your situation would have been to manually move/name the files to the location MC was expecting to find them. Either solution would work, you just choose the path of least resistance.
There is also the option to "fix or remove broken links" on the import media dialogue (file > library > import media) but in my experience, it always removes the entries, and in this scenario, you really wouldn't want it to do that unless you don't mind losing associated data not saved in the file's tags, such as [date imported]. As far as I'm aware, those are your only options.
This is all well and good, but if I were you, I'd be just as concerned about how the links got broken as I would be about fixing them. The underscore in the filename is not a problem, the slash is an illegal filename character in windows, so an underscore is used instead.
I can't tell you what happened regarding your 5 files. instead, I'll type a few things and perhaps something will click with you.
The first thing you should be aware of is that as soon as you click the OK button on the rffp dialogue, MC updates the filename field, then it sets about moving/renaming those files. If something happens to break the rename process before it is finished, then you will find yourself in exactly the situation you describe above, because the filename field in your database will not be rolled back.
So, what kind of things could interupt the process?
Well, the blindingly obvious first, being a system crash or a powercut, that kind of thing.
You should always avoid using the rffp tool on files that are being played, or could possibly be played, during the process. Theoretically, it shouldn't matter, but I always follow that rule when using this tool.
A long time ago, I was able to break the process within MC by setting it in motion, then starting another rffp job before this first task completed. In this case, MC would immediately abandon the first task and begin work on the new task. The [filename] field would not be rolled back, and broken links would be the result.
Now, this may well be fixed now, I'm not sure. I prefer simply not to do that. When you start a rffp job, keep an eye on the status bar at the bottom of the MC window. It will tell you if the job is finished, and if not, it will tell you how far on it is (saving tags x of y) When this changes to 'done saving tag changes' the job is done and you are free to start another.
If you were only changing the filename, not actually moving the file, you'd be hard pushed to get another rffp job on the go before it finished as the change would be practically instantaneous. The only things that might, possibly, slow that down would be if the files contained no existing tags, or resided on a remote machine (server)
The tool works in exactly the same way as windows explorer would, so, if you were moving files, and you were moving them to a different place on the same drive, it too would be practically instantaneous, barring the same possible limitations above, whereas moving them to a different physical drive, or partition, would take a while longer. How much longer would be determined by things like the total size of all selected files and drive speed.
The rffp tool offers an awesome level of control over your media files, and as such, should be treated with some considerable respect.
Following the tips above should afford you error free results from the tool, and help you gauge a rough idea of how long the job might take to finish. Just to be clear, you should be safe enough playing other files and generally poking around in the library, just don't start another rffp job untill the previous one has finished. I cannot remember the last time rffp let me down. I'm almost certain it was away back when, before I put these groundrules into practice myself. The way I visualise it is that while the job is in progress, the files are effectively 'broken links', so this area of your library is in an extremely volatile state during the renaming process. Prepare the area before starting the job, and after starting the job, don't do anything else in this area untill the job has finished.
I think I've covered everything there; remember, none of my files are on a remote system. You may also be well aware of all of this already, bearing in mind you didn't actually ask for "recommended practices" when using the rffp tool.
If you work out what went wrong, could you let us know here. I know I'd be interested.
regards,
-marko.