I have had some issues with the Desura client and I know that others on these forums have also had issues. In another topic, I discussed some of the ways I had been working around my issues. Today I was working on activating some games I got as a part of the LazyGuys Bundle. While doing that I realized that the Desura client was again working as it should. I was able to activate games through the client, browse through their catalog of games, etc. After a long period where I could play games, but not do some of the other functions using the client, this was a welcome change.
I thought I would mention this as others that have been having problems may want to try again to see if the client works for you.