Attachment issues

I posted a few days back, but didn’t get a response. Can anyone point me
in the right direction here?

RT 3.8.2, PERL 5.10.0; MySQL 5.x; Fedora 10

I have followed the instructions in UPGRADING.mysql (although I did so
after the fact; my RT was installed via yum/RPM).

Images, PDFs all seem to store correctly. Office documents do not. I
noticed their MIME types are text/plain, while images and PDFs MIME
types are as appropriate for the type. The Attachments table looks
correct with the default char type of utf8 (which confuses me; the
script in UPGRADING creates a script that sets default char set to utf8,
yet there is all sort of warnings in the doc not to set default char set
to utf8).

Can anyone help me clear up my confusion here?