Map built in Photoshop blurs on timeline

I have built a map in Photoshop by joining screen prints of Google Maps. I find that when imported into Premiere 5.5 it blurs when played on the timeline.  The image size is 3752×2169 and is 8.6MB in size.  I have experimented with different pixel densities with the same result.  Exporting the timeline as  H.264 and reimporting gives the same result so I suspect that it will appear like this on my Bluray disk.

The project settings are PAL 1920×1080 50 fps Progressive

I have never noticed this phenomenon with still photos. Is there a way to fix this?

Alistair

via Adobe Community : Popular Discussions – Adobe Premiere Forums http://forums.adobe.com/thread/1092067