combination of 2 themes in wordpress

Hi, I got an idea this morning of combining 2 different themes in one wp website. I found the plugin and installed it. Works fine when each theme is setup for different page. But. There is a problem. And therr might be solution, but I did not find it by searching the web.

With above I want to create frontpage using my default theme with widgets from other theme. Everything is setup but it just does not work.
Any suggestions?