A long time ago I accidentally added an "English (Australia)" dictionary to Chrome's spell checker. Unfortunately, I can't find a way to eliminate it.
I've already uninstalled Chrome several times, cleaned remaining files, removed every possible keys on registry (I think) and only then I did a clean install.
Yet, the dictionary remains there, annoying me every time I change the language.
One strange thing is that if I add another language and then remove it, it happens as expected and it IS removed. However, with EN-AU, it doesn't. I can't get rid of that and this is pissing me off. Does anyone have any idea about this?

Had a look myself, have you tried adding another language (or using one you want as the primary language), setting it as the language for displaying Chrome in, and for spell-checking with, then removing the Australian one?

Yes, a few times. I'll try a few more just in case.

Have you tried manually removing Chrome according to their options?

Beyond that I tried replicating this weird error, added Eng (Aus) and removed it successfully by clicking the X.

Running latest Chrome dev build.

http://www.google.com/support/chrome/bin/answer.py?answer=111899

Yes, I did remove everything manually, tried a few "uninstaller apps", used that reg file, I even searched for other reg keys and deleted by hand... nothing works. I was running the Dev build, rolled back to stable, the problem persists.