Trouble with .bam files and freezing spellbook icons.

I've just completed the design work on 140 spell icons, now I'm ready to convert them to .bam files.

I'm using both versions of BAMWorkshop, using the supplied palettes, with dimensions set to a maximum of 32x32 pixels and they show up perfectly in the BAMWorkshop preview. I can see them against the test backgrounds, so they should work fine.

That is until I assign them to a .spl file. Instead of showing up like they should, there is a blank space that freezes the game when you click on it.

I've tried to follow the tutorials out there on .bam creation but I must be missing a step in the process. I could send these 140 (280 in total) files to someone else to convert them but I rather be able to do this, as I'll be adding more icons in the future and that's its just generally quicker to do it all in house.