Multisite & Multinetwork – Upload Error

I am currently running a wordpress multisite network on version 3.2.1. It has two networks setup via the Networks for WordPress plugin.

On the original network, uploads via both the flash uploader and browser uploader work properly.

On the new network, uploads do not work through either uploader. In an attempt to narrow down the problem on the new network, I disabled SSL (the certificate was invalid and being used for testing), which resulted in a change to the error message.

With SSL enabled, the errors I receive during an upload attempt in the media library are;

Flash Uploader: IO error.
Browser Uploaded: Error saving media attachment.

With SSL disabled, I receive the following errors;

Flash Uploader: “image.png” has failed to upload due to an error. Sorry, this file type is not permitted for security reasons.
Browser Uploader: Error saving media attachment.

The file type I use is irrelevant, it will fail regardless of format with a format error.

There are two sites on the new network, and the same symptoms occur on both. They were originally on the old network but were migrated to the new one.

Oddly enough, an import (of posts) from under the tools menu works just fine.