White page before anything else

Hello I recently moved to dreamhost. Since configuring my WP there I have an annoying problem that’s sending my stats donw the toilet :

when me or another visitor wants to visit my WP blog first the server
sends a white page withe absolutely nothing on it, but not a 404.

If he/she reloads the WP shows up in all its glory. But he/she has to be smart or web savvy to do that. Not all my visitors are like that.

It does not look like this is a wp_cache problem (activating/deactivating it) does not soleve the problem.

Did someone encouter something similar ? Is there a known cure ?

thanks in advance