save changes made in style sheets

[pp]

Hey,
I have trouble changing changes made in style sheets for reports or 
creating new ones. I can make changes or create new style sheets and 
they show in reports when I reload those but all is lost once I close 
and reopen the program. I'm using GnuCash 2.6.17 on a windows machine. I 
found the folder where GnuCash stores the default style sheets, but I 
can never find a file with my custom style sheets. What am I missing?

Thanks for any help!