Trouble Uploading Certain types of files

I’m wanking about with BlogDesk and BlogWriter blog clients. Both are pretty nice, but both have a problem with DirectUpload, which I am thinking means the problem is really in WP and/or the server setup…

Actually, both also support FTP uploads, and these do in fact work, but for a specific project I want the WP DirectUpload to be used, so I’m working toward that end.

We’re talking about links in the posted message – for example, an document in PDF format.

Some files will upload okay – pictures (jpg, gif, probably others although I haven’t tried others yet) work, as do .txt files. It looks like MS .doc files work, but neither PDF nor Open Office .odt will post – they generate xmlrpc errors. .doc files upload okay.

In the wp-admin post/edit upload of .doc works, upload of .pdf works, but .odt is rejected with the message: “File type does not meet security guidelines” – yup, yup, .doc files are okay despite the notorious macro exploits, but .odt files don’t meet security guidelines.

I have two questions: (1) what might I try to do about the problem with the xmlrpc upload failure, and (2) how do I whack the security guideline into accepting .odt files?

WP servers are my own and a client’s Fedora Core 4 machines with virtual domain hosting.