Does the problem lie with WordPress
-I am not aware of such problem with WordPress. I use 3.0.3 with the default Twenty Ten Theme, no such problem
or the web hosting?
contact your hosting provider to find out.
-If the problem is caused by any plug(s) you are using, to find out try deactivating ALL plugins temporarily to narrow down and possibly fix the problem. If the problem goes away, activate them individually to find the culprit.
- If the problem is specific to your theme, to find out try switching to the default theme ("twentyten") for a moment by renaming your current theme's folder in wp-content/themes. The idea is to force WordPress to fall back to the default theme to rule out any theme-specific issue