Running the current version of K3B (v2.0.2) on Xubuntu Oneiric, I wasn't able to input the ISRC code for an audio track:
It allowed me the first 2 letters (uppercase!) and then I couldn't input anything more
[SOLUTION]
I thought it might be a bug, but it's a feature! K3B *requires* the hyphens within the ISRC - and you have to input them manually, or copy/paste them in the *exact* correct format. Like this:
Thanks to a post by user "Kitserve" on Ubuntuforums.org, that cleared this up.AT-V72-12-03001