Sorting of files with more than 99 files

[simply mod]

Hello everybody,
I'm using Rockbox 3.13 on a SanDisk Sansa Clip Zip and although I'm satisfied with music playback and the general usage I just recently stumbled upon a problem. Some weeks ago I wanted to listen to an audio book which had about 220 single mp3 files as opposed to the usual 10-25 when listening to music albums (I only listen to whole albums one at a time so no custom playlists or shuffle everything like some people tend to do). When adding the files via Database -> Artist -> etc. they are added in this order:
1 -> 2 -> [...] -> 9 -> 10 -> 100 -> 101 -> 102 -> 103 -> 104 -> [...] -> 109 -> 11 -> 110 -> 111 -> [...] 119 -> 12 -> 120 and so on.
When adding the tracks via the file explorer this doesn't happen.
My files are tagged like this
Artist = Author
Album = Book
Titlename = Book (yeah, it's just the same as Album)
Tracknumber = Sequential Number

The files are named Author - Book - Track

I tried adding leading zeros to the track numbers to make them 3-digit-numbers for every track but this didn't work.
For my music I use Artis - Album - Titlename - Tracknumber and it works fine so in general Rockbox does this sorting in the right way.
I tried switching between interpreting numbers as digits and whole numbers (Chapter 8.2 in the manual) but this didn't help.

Does anybody else notice this behaviour? I'm a bit sad about this although I do have my workaround which just works.

Kind regards,
simply mod

[fredex]

I've never tried creating a playlist directly on Rockbox, it seems to me that it would be cumbersome (but not having tried, I wouldn't really know, would I?)

I use a tool on Linux to create the playlists, and as long as the numeric portions of the filenames are all the same number of digits (leading zeroes, as you tried) they come out in the right order.

Or I can manually move lines around in the playlist in a Linux text editor if need be.

Having done that, the sorting (if any) Rockbox uses in the file order within the directory is moot.