This is something that i have posted on their forum also:
The problem is that some of our clients are reporting incomplete downloads for the ZIP archives available for download on our website ( you can test for yourself by creating an account on www.extendstudio.com and downloading the trial versions).
Unfortunately i can't reproduce the problem in order to give you an example, for me everithing works perfectly. Searching the net for this particular issue i found that this problem is reported by other MediaTemple clients also.
Catalin Serban,
www.extendstudio.com