Slow startup when opening a file in a highly populated folder

[ghost]

I have a folder on my computer which contains over 15,000 images. When I open any image in this folder with JPEGView, it takes a very long time (1-2 seconds) to start up and display the image. If I copy the same image to the desktop, it opens instantly.
I'm guessing this is because it needs to obtain/process a list of files for the back & forward functionality (which I want to keep and not disable). I know this is not an impossible problem, because Windows Photo Viewer works just fine without any crippling delays (although it does fail to parse many file types, hence why I want to use JPEGview).
Can this file listing be sped up, or moved to another thread?
I'm running Windows 7 with the 64-bits version of JPEGView.
Thanks.

Version 1.2.45.0, but it also happened on an old version before I decided to update to see whether it would fix the problem.

Edit: After some more usage, this problem becomes totally crippling and the software becomes unusable when the large folder in question is accessed through a network drive.

[sylikc]

PR #172 is supposed to have modifications which helps with this. I haven't had a chance to review it yet... But I recall possibly having to add more code to make it more robust.

It should take care of this problem when it merges