The extra DLC is not missing from the Gamersgate version, as it is all free now. What IS wrong with the Gamersgate version is that it is not fully patched. 1.69 is the latest and includes all the premium modules for free, the GG version is 1.66. Simply needs to be patched. Follow this link http://social.bioware.com/forum/1/to.../index/3341490
If the module you're after isn't in, you can just download any of them and while it will try to authenticate that you bought them, it will fail and you'll still be able to play. Don't click demo.