Hi, thanks for posting.. could you be a bit more specific? which CTM version are you exporting to? what is the resulting problem? if exporting to CTM5 then I can tell you that this format does not support tile tags or names, I should probably put in some friendly warnings about unsupported features when exporting to older project formats.
I will examine this and post more symptoms.
There is one thing slightly related to this, check this file:
https://github.com/c64lib/gradle-retro-assembler-plugin/blob/6776eaeb9654f6dc534...
(click "Raw" to download binary CTM).
it is CTM 8, text mc, with tiles. Charpad 3.0 BETA#3 shows three tiles with tags 0, 0, 4 respectively. But it fact it is 0, 2, 4 (it is how it is stored in CTM file, I'm pretty sure about it. By some reason, tag for second tile is shown as 0.
Thanks for the bug report Maciej, I have tracked down the problem and nailed it. The tile editor's constructor was zeroing the current item (1) after loading a new project. The fault was present in the Win32/64 versions and also affected SpritePad and the last released CharPad 2.xx releases. I will put out some updates in a few days. Nice catch ;)