Blank Admin Page after logging in!

I am getting a blank page when I log into the Admin eg. www.mysamplestore/admin/ Nothing comes up at all. I get a blank page... The top of the Page, above where I type the URL is Zen Cart! but the actual page is blank/white!

If I reload the page sometimes it comes up correctly, but it is just not acceptable... What I have found is by typing in another location, i.e., www.mysamplestore/admin/admin.php I can get that page to come up and then from there I can begin navigating my way around.

I am using Safari but have found the problem in Firefox too! I should mention that sometimes I can log in without any problems... But it seems like these days I get a blank screen more times than the right screen.

I am in the process of teaching others how to use the Admin and they need to be able to log in without problems...

Can anyone help with this?

have the host reset apache and mysql,
its overloaded

Thank you! That did the trick!