FYI: I'm installing the latest build (20080702) with php v 5.2.6 and mySQL v 5.051 using 1and1 shared hosting services professional package.
So far, the install went well after discovering I had to modify my .htaccess file to direct the server to interpret all .php with php version 5. 1and1's apache configuration parses all .php extensions with version 4 by default. For those on hosts with multiple version of php, add the following line to .htaccess at moodle's root: AddType x-mapp-php5 .php
This will clear all register_globals tests, but the optional xmlrpc flag isn't working on my install.
Now, the error I'm getting, Could not assign moodle/site:doanything to the admin role, is caused for a simple reason. When I set up my table prefix, I used a mix of CAPS and lowercase - the moodle install forced all letters to lowercase when creating new tables, near the end of the install, it called my mixed CAPS/lower prefix in a SELECT query and failed to find the table due to the mix!
So, word to the wise - don't use CAPS in your table prefix during set up!