I have an older version of XML-Sitemaps that now has some problems.  So I have installed V4 in a new folder. 
When I start generator, and make some changes to the default config (such as adding a login and password) it does not save any of my configuration .  So, I can not logout, nor can I run a crawl.  When I ask it to run a crawl, it bounces me back to the index.php page.
Although I do see  the file
/data/generator.conf
being created, it does NOT hold any of my specific configuration requests. 
I am on Linux, and I have verified the attributes
/generator/data/  777
Any ideas?