Invalid argument supplied for foreach

This is the message display in my site:

Warning: Invalid argument supplied for foreach() in /home/polyuspa/blog/wp-settings.php on line 113

I just follow the instruction to start the frist time setup. Except the necessary information i have enter on the config.php, there are no changes i have ever made.

the problem i have is every time I log-in/click the ‘Dashboard’ optoin in the admin page, it take about 2-3 mins before i can get into the page. Other thing seems to work fine and will have immediate respond after a click.

Also, there is an erron message on the ‘admin-plugins’ page:
Warning: Invalid argument supplied for foreach() in /home/polyuspa/blog/wp-admin/plugins.php on line 32

is that my configration problem or the host server problem? thanks