Short answer: Yes
Long answer: while we do support PHP5.3.x this is on limited servers only, because many standard scripts do not work in PHP5.3.x anymore a lot of our shared servers will still work with the latest PHP5.2.x vesions. We have setup some new PHP5.3.x servers for those who need it.
For dedicated servers there is always the choice of the client between PHP 5.2.x or PHP5.3.x
(during the setup process you will be asked which version is prefered by you so we can create your account on the right servers, if you are already located on a PHP5.2.x server you can request a transfer at our support department).
