The Images will not work with GD2 2.028 or below as I tested this and that is correct because they are invalid jpeg files as far as the image processor is concerned. I can not say whether GD 2.0.33 resolves this but I would say NO since it was released in 2004 and is there latest build.
I would just like to clarify here this is not an issue with the Photopost Gallery Software. Any Gallery software you look at will have this same issue with those images since all gallery software is reliant on either GD2 or ImageMagick for Image Processing.
Now since this deals with the Image Processing software which is a server software as long as you are using the latest ImageMagick on your server you will be fine uploading those images. I would suggest if you purchase Photopost you use it on a hosting environment where you have the ability to compile your own software and you can compile Imagemagick yourself to know you have a version that will work with them.
There are many good host's out there and ones like the one I use which is
http://www.westhost.com which have great features and decent pricing for shared accounts if your not quite up to the dedicated server scene yet. I can compile whatever software I want on my VPS server because although its a top line shared account it is its own private server space.
Here are the ImageMagick installation docs on our site here which show how to install Imagemagick
http://www.photopost.com/howtoinstall-php.html
I hope the above explanation clarifies the nature of this issue for you and puts any apprehensions to rest that you have.