I have found a temporary solution to the disappearance of my Archives page. I'll have to toy around with my template (yet again) in order to see if I can fix it, but that'll be only once the whole categorizing thing is done. Same goes for the size of the "Labels" text at the end of each post and for the "Greatest Hits" category listed in the table to the right.

New Blogger seems weird to me, I sure hope things'll smooth up once the whole upgrade is completed on my part.