I hopped on the forums to see if updating my gameEX would fix the issue, but I see that others are having it also. I can't be specific about when it started happening but we are frequent users of steam launched through gameEX and have been experiencing the issue fairly recently as described by @mistermorcusverbatim. I did a google search and it does seem that steam may have made a recent update to their overlay as their is buzz about it on youtube about a month ago.