Originally, settings for album objects were saved in "fileVariables". A few years ago, this was replaced by "AlbumObject" and fileVariables is now deprecated although it is still supported. FileVariables is still used by BluPlusPlus.
Although jAlbum 15 did not change how it uses fileVariables, something is now broken. There was some discussion in
http://jalbum.net/forum/thread.jspa?threadID=53338. We cannot produce this problem consistently, so it is difficult for David to diagnose it.
I am working on the next version of BPP. This uses AlbumObjects and it does not have the problem that you described. I hope to publish this in about 1 week.
The workaround is to use jAlbum 14.1. Download the zipped version and unzip it into a different folder (e.g. jalbum14 instead of jalbum).