Filenames of duplicated menus

Question

I have Encore CS3.  I had two menus called "Romaji Songset Menu 1" and "Romaji Songset Menu 2" (I'll shorten that to "RSM" here), and I duplicated them and renamed the copies "Japanese Songset Menu 1" and "Japanese Songset Menu 2" (hereafter "JSM").  Since then, I have been having some funny problems with at least one of those copied menus (like text reflecting the button name even when that checkbox is not checked, or all my navigation suddenly going to zero on a whole menu without warning, etc.).  Just now I happened to look in the Menus directory at the actual files, and noticed that the filenames did not change when I renamed "Romaji" to "Japanese".  The filenames are currently called "RSM 1", "RSM 2", "RSM 1 2" and "RSM 2 3".  And there are other files in the same directory that are older, and they seem to correspond to times when I duplicated menus and then deleted them later - apparently the actual files are not removed from the directory.  Those older files also apparently had the same problem of not being renamed when renamed in Encore - they have names like "RSM 2 2" (from a previous duplication of "RSM 2") and "RIM 2", "RIM 2 2", and "RIM 2 2 2" (I don't remember duplicating my real "RIM" menu that many times, but I suppose it's possible).  There is even a "Top Menu 2", and I don't remember duplicating the top menu at all.
I don't think I had this problem before - I have a project from last fall that also involved duplicating menus, and all the menu files are named the way they should be.
The question is, is this harmless, or could it be related to the other strange problems and should be remedied?  If I rename the physical files, Encore will probably orphan any related links, zero out those menus' button navigation, etc. - who knows what havoc that would wreak.  I am in final testing of the project before sending it off to be made into a DLT for the replicator, and things were looking pretty good until I tried to use one of my menus today and discovered that all the navigation was gone.  I fixed that, but if I don't know why it happened, and if it happens again when the DLT provider opens the Encore project, yikes!
And should I delete the files with old dates, or could there be some sort of umbilical cord between them and the currently used ones?
CORRECTION: I just discovered that the navigation-becoming-all-zeros problem was on not just one but both JSM menus, so there is definitely a disease that duplicated menus have that originals don't, in my case.

Answer 1

@John: I hear you, and from now on I'll use simpler filenames (no spaces and shorter).  But I had the exact same menu file naming convention in a previous project last year, and neither then nor now have I had any of the blatant problems cited in the threads you referenced - I have not gotten any errors whatsoever in this project (knock on wood), and the test DVD's play fine.  By the way, Encore itself is an offender of the "no spaces rule" - notice that the additional numbers it adds have a space in front of them!  I guess if we want to avoid spaces in filenames, we cannot ever use Encore to duplicate menus...
Followup question: If I decide to rename my files to play it safe, how much additional work will I make for myself, and what landmines might there be?  I'll have to re-import all the menus, relink all the buttons to and from each menu, and recreate all the navigation, right?  Anything else?  I have seven menus and a zillion buttons, and I was hoping this project was at its final stage (I actually thought I would have been sending it out yesterday, but my husband found some things to be improved in the videos, and we also noticed that the default button on the menus was not what it should be).  And my asset filenames might give you even more heebee-jeebees (I've never spelled that before - it's just something my mom used to say), as they mostly consist of multibyte characters - but although that might bother you, it is perfectly normal for all Japanese users of PPro and Encore.  I am not going to rename all of them!
@Stan:
The not renaming the file name is exactly what EN does: simply renaming
the menu in the properties panel does nothing other than to change the
name in EN. ... To the extent that it matters, if I really want a filename difference, I
save the menu (as file or template), then import as menu.
Hmm, I guess when I did the same structure of project last year, I must have copied the menu files and imported, rather than duplicating within Encore.  Perhaps I was smarter last year... LOL
EN is not designed for us to go  messing around in those directories (even though we do/must).
That's exactly what I'm afraid of with John's suggestion that I rename my files.  Things are working at the moment. (I feel like if I sneeze something might go wrong, but at the moment it's okay.)
I wonder if your navigation was lost as part of that process?
Nope.  The menu was duplicated over a week ago, and the navigation was fine.  Since then I have made many changes, and the navigation stayed fine.   (I edit in Photoshop, but I never open the files outside Encore, as I'm  afraid of the delicate relationship - I always run Encore and select  "Edit Menu in Photoshop".)  The time when the navigation went away, the only thing I did was to change the default button from 1 to 3 on all four Songset menus, and from 1 to 2 on two other menus.  At that time I made no other changes, and did not open the menus in Photoshop at all.  After only the default button change, the two previously duplicated menus lost their navigation, but all other menus were okay.  That's why I was wondering if there was something special about menus whose filenames have additional numbers that Encore adds when it does duplication.  I don't care about asthetics of filenames or extra files in the folder - I just want to know that my project will run when I send it off to be made into a DLT.