Hi,
Not sure if this has been covered anywhere else or if this is the right place to put this but I wanted to put it out there for people who might be affected by the issue we were.
One of our servers is a Media Temple DV Server. At current it only has PHP4 active thus Silverstripe wouldn't work. We were very keen to try Magento which also only supports PHP5, However in the Magento Knowledge Base there is a guide to install Magento through the PHP5 CGI wrapper.
On installing Magento through this guide I gave Silverstripe a try and it worked flawlessly. So if you are stuck on PHP4 and have the chance to use the PHP5 CGI wrapper it will work.
Here is the link for those who are interested.
http://www.magentocommerce.com/knowledge-base/entry/installing-magento-on-a-php4-server
cheers
BD