I export all my images to Zenfolio with nominal 850 x 1100 pixels from Lightroom. Zenfolio displays them at different sizes depending on the aspect ratio. If the aspect ratio is 3:2 then it looks correct (1100x732 pixels). If its anything else it looks smaller. Say an image that is 4:5 aspect ratio. The vertical should be 850 and the horizontal something less. Yet it is displayed with the vertical smaller than a 3:2 aspect ratio with 850 pixel vertical height. In fact I have one image that has a one pixel crop so it is 1099x850. This image is shown much smaller than the 3:2 image that is 1100x732.

Why is it like this and can I correct it or is a bug.

If you can please send an email to support@zenfolio.com and include a link to an image you are having problems with, we can take a closer look at this for you.

edit:  After posting the examples below I found the answer posted here:
http://forums.zenfolio.com/forums/p/2657/13850.aspx#13850

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Gerald the answer seems that zenfolio does not dynamically resize the pictures. It creates several fixed sizes then picks the size that best fills the space. It's been that way since at least 2009 and it does not look like zen is changing any time soon. You can live with it, work with it (as zenbrian does in his landscape gallery but making every picture the same size with black bars on the size for the portrait orientations) or find another solution that resizes better.

Here's what I originally posted as samples:  

Zenbrian 

I noticed this on the first gallery I uploaded to zenfolio.

You can see it in your own gallery:

Thanks for you inputs trikster2. I see now if I scale the window size up and down then the images re-size in jumps and also the relative sizes of the images look OK. I think this is what you mean by not dynamically resizing. That is OK for me. However there does seem still to be a miscalculation of image size in the full screen state. When full screen it selects a too small size for anything that is not standard ratio.