NewBlogTemplates and Default template problem.

Hi, i have one problem, i want to make blog on my subdomain for ex. demo.bettingtip.info and them to set up it to appear like starting blog design for all new created blogs, i use New Blog templates.

(i want to it be only choice and to dont allow users to change theme)

BUT, when i delete all other themes from network admin, i only keep frontier theme (network activated) then i tried to make new blog but there was only blank page, but when from network admin click on activate frontier theme site work!

Then i instaled default templete and solve that problem, all new blogs was in frontier with no option to change theme, BUT when i instaled New Blog Themplates and set up default.bettingtip.info as default templete it doesent work! i made small changes on default.bettingtip.info but when i create new blog that is not like default.. what can be problem