What are your project settings (not just the export settings)?
If the project settings are interlaced, and you set the export Field
Order to None (Progressive), Pr will try to deinterlace the footage on
export. When that happens you lose half your resolution.
The key is to set up a project that is progressive and export from
that. To preserve the work you've already done, simply import the
existing project into the new progressive project.
I did actually start the project settings off with all the right settings including 30 frames, 0.9 ratio and progressive. The problem was that I have a habit of always checking the deinterlace video box because I can't stand interlaced video. Unchecking this box in the top left corner of the Media Encoder window fixed everything. Thanks a ton!