I have installed TestLink version 1.9.7 in fresh installation using the automated mode. When I log in to the login page I get the upper menu but the main body of the page is blank. When I read the source, I see that indeed there are two frames, the upper frame points to navBar.php and loads but the main body points to mainPage.php but does not load. If I try to go to mainPage.php manually it redirects to another page (I can see in the URL) but the page is again blank and absolutely nothing in the source.
I fixed a similar problems with a fresh installation of TestLink 1.9.8.
Removing the module php5-adodb fixed it for me - post I wrote about it