Hey..
I thought I'd try what Falkon said he did with his de sol - and try to locate the black tube under the glove compartment.
I found it, and squeezed it a bit. Made a bit of a crunching sound while I did that.. and now the problem's gone.
I'm sure it'll return in time though, until I can get the condensation tube properly cleaned out.
But for now, that's cool. Thanks Falkon and others!