Are you facing downloading issues with CS5 from adobe.com?
www.adobe.com uses Akamai Download Manager to download the trial versions of software. There are some reports of users running into issues while downloading from the same website.
A Technote has been released which guides users to overcome the download issues which can be found at
kb2.adobe.com/cps/526/cpsid_52698.html. A more detailed FAQ page can be found at