As I suspected might happen, the developers have finally responded to the bug that set this issue off, with a WONTFIX.
The issue is now getting a little wider exposure in the media, along with news of a fork – the rather lamely named funpidgin. While I’m always happy to see a fork – and there was certainly good reason to create this one, given that the change makes Pidgin so utterly annoying to use – I’m not entirely convinced that this one will go all that far.
A simpler way to fix the problem would be to use Artemy Kapitula’s manualsize plugin – except that it had to be compiled as part of the pidgin source code, which was a bit of a pain. I have now created a standalone tarball of it, along with a Debian package. An Ubuntu package will be coming soon, when I’m not stuck using Australia’s pathetic satellite broadband service. Users of Ubuntu Hardy Heron will probably want to use this package, as it is too late for it to be included in the forthcoming Guifications plugin pack, for them.