Can't always pad track numbers

As part of an effort to standardize tags, I want to pad all tracknumbers to two digits (some of my older rips were not tagged this way). Easy enough....most of the time, I simply click on the action that applies the formatting and it's done.

But sometimes, I come across an album where I absolutely cannot seem to change the single-digit numbers. The action doesn't work, manually changing them doesn't work....nothing. I simply can't turn a "1" for example, into a "01" no matter what I do. It seems so random, and it's incredibly frustrating!

Any ideas why this happens? Or more importantly, how to fix it?

i can of two causes:

  • you have mp4 files that do not allow padding
  • you have files with ape tags which show first but you write only mp3 tags (which are not shown)

What type of file and type of tags?

FWIW, I've standardized on exactly the opposite, and treat all tracknumber fields as integers, not strings. Any 01, 02, or 01/13, 02/13 etc. are turned into 1, 2, etc. I've yet to find a single application that needs tracknumbers to be padded in order to sort them correctly. The only place I pad the numbers is in the file name, where it's necessary for the operating system's sorting of file names.

All my files are m4a ALAC, and with most I can format the track numbers just fine. But occasionally, some exhibit this weird issue. I've tried everything I can think of, including removing the tag completely and then adding it back.

And it's just the track tag formatting. For opera titles, I include act and "song" in the title, like this:

I-08 Duett BeMännern, welche Liebe fühlen

If this were one of those albums where I can't pad the track number, it would show as "8" in column view, extended tags, etc. And I can't get that to change. But when I use it as part of the title, it'll take the re-formatting....i.e., this comes out right:

format title: %util%-$num(%track%,2) %title%

  (%util% is an internal tag I use, in this case for act number)

It's not a huge deal, obviously. But it's just so bizarre and I'd really like to know why it happens (and how to fix it).