I installed jAlbum for iPhone yesterday and it seem to work just fine, I can go to my site (self-hosted) and view the albums. I can see the thumbnails but when I tap one to see a larger version it looks like the app is trying to download it but nothing happens.
I have seen this flaw when viewing self-hosted albums where the photos are placed in sub-folders, but I haven't figured out what the reason is. When this happens you can flip back and forth betweeen the slides, and then the thumbnails will be loaded, but scaled up and thus fuzzy, but the slides will never load.
Have you access to the webserver logs, and can see if you get any hints there?
We will probably release an update of the app in a month or so (with iPhone 5 support) and I will try to fix this bug in that release.