If you have any WordPress blogs on 1and1 then you’ve probably ran into some problems with updating certain plugins, updating the blog, or even importing to your blog. The reason is because 1and1 has some issue with PHP4 but there is an easy fix. You need to hand edit your .htaccess file (located in the root of your WordPress directory). Here you will add the line, AddType x-mapp-php5 .php to the end of the file. It doesn’t matter too much where you put it, so it’s best just to put it at the end.
Let us know if this helps you out or not.