Some videos are semi-missing - they do not show up in File Manager apps or another app

Question

I have what I will call three FILER apps: File Browser, Air Browser and File Commander.  I also have MovieSRTPlayer.  Those apps appear to not register the presence of some video files that I have definitely copied to my PB.  The MovieSRTPlayer will overlay a .srt file's text over a video allowing the pb to show subtitles.  It works as long as it can find the video and srt files.
I am definitely transferring a series of video files to the pb's video folder.  I am also transferring a companion file to that folder.  The companion file is a subtitle file in the form of an .SRT file.
THREE file manager type apps do NOT show those files as present in the video folder.  The Video app itself does show and play those video files. 
I have copied the files using both wifi-sharing and when they did not show up that way, I copied them using the usb cable to the pb's Z: drive and the video folder.
As stated the dam! files play in the video app.  But they do not appear in the various filer apps.  And they also do not show in another app, one that will display the subtitle (.srt file) file overlaying the video.  In all instances it is as if the pb does not register the presence of those files on the pb.
Now, what is interesting is that when this first cropped up, 7 files were missing - just a mix of video (no .srt files involved).  That is they showed in the video app and played but the filer programs did not show them.  I managed last night and this morning to get 7 of those to finally show by copying/moving/deleting and recopying.  But now I'm running into this brick wall again.  I have repeatedly copied two video (avi files) and their companion .srt files to the video folder.  They are in that folder (I've looked using usb and wifi-sharing) and they play in the PB's video app.  They are most certainly on my pb.
Oh, and yes, I've rebooted a number of times. 
Ideas?

Answer 1

I have what I call 3 file manager apps.  File Browser, Air Browser and File Commander (the older free version). 
They all show or don't show the same thing.  So files are missing.  And SIZE is not the sole determining factor.  When I was testing MovieSRT and "lost" some files I copied and renamed avi and .srt files.  So there are two extra .srt files in the Video folder.  But while they are 32kb (kilobytes) and 58kb respectively, they do NOT show up in the File managers.  The other two identical files with the names matching the .avi files do show up.  The one very large mp4 (2gb) does not show up.  A subfolder I created just as a test does not show up.  But the large mp4 and subfolder were showing up while I was actively copying the 2gb file - they would show up as the file was being copied - the filemanagers showed the file getting larger and larger and while doing so the "missing" subfolder also kept showing up.  Then once the large file was completely copied, both it and the subfolder "disappeared" - again, the large mp4 does show in the Video app and it plays.
My persistence probably is based on the fact I was a computer programmer many eons ago!  Also, I was trying to get YOUR app to work and the avi files were not showing up in your listing but they were showing and playing in Video app (but no subtitles).  Finally, after copying/moving/re-copying over and over including moving and copying to the PB's Print folder (just since it was empty) and copying it back to the video folder (now 2 copies), the files would finally show up.  Peculiar - yup!
Oh, one other thing - the 3 file managers all show what I will call the virtual Playbook-Demo video in their listings - your app does NOT show it.  Obviously, it is not located in the Video Folder but somewhere in the bowels of the PB.  So, the filemanagers  are relying on some "file structure" that is not fully correct.  But your app does not appear to show it.