Hey Colin-
Do you have your own Pachy install or are you using a hosted service?
If you have your own server, depending on when you downloaded Pachyderm, you may have a copy with a root.swf saved in Flash 8 rather than 7. Right now the Flash 8 root automatically smoothes (a "feature"

. You can try replacing your root with the one attached and see if that helps anything.
If you want to go with the hand resizing approach, I use this myself from time to time, you will probably need to do a little research. One easy way to do it is to look in the directory of a presentation you have published. All of file names for the derivative image swf's contain the image sizes. You could note them from there.
If you do end up doing an size inventory, please post it or send it to me so I can add it to the template spec section of the site.
All best,
Scott
File Attachment: File Name:
root.swfFile Size: 327501