I found I had all kinds of issues beyond what I posted above. In addition to what I listed so far, proximity mines would trigger but never explode. Stand-alones would not run, they would freeze while loading, and it also would not connect to the store, even though I was logged in. It would give one of two errors: "Invalid email or password (Error 1147)" or "User not registered on the Game Guru Store, please click the Game Guru Store buton etc., etc." Also, prompts would stay on screen until I triggered a different prompt. Nothing posted in this thread helped, although they were all good suggestions. (Thank you!) I did finally get it working, however, I do not know exactly what I did, or perhaps it was a combination of the things I did. I uninstalled GG, and let Steam re-install it. Upon the reinstall, it worked (or didn't work) same as before. I then stopped several processes in an effort to find one that was hurting me, to no avail. I then rebooted, along with a windows update, then launched GG again. Everything above works now as it should, with the exception of the GameGuru Store. I still get those same errors. Bummer, I got paid today! LOL!
It would seem that the windows update fixed my issue, but I can assure you I have rebooted my laptop many, many times since this issue first showed itself, and upon each reboot, there was no prompt to update until this last time. I find it hard, if not impossible, to believe that in the midst of all this, Microsoft released an update that coincidentally solved my problem since I am absolutely certain this GG update was developed BEFORE the Windows update was released! Anyway, I hope it stays working, and I hope you figure yours out too, Pink Panther. (Now I have the Pink Panther song going through my head.) I still have the issue on my desktop, since I am writing this only minutes after resolving it on my laptop. I may be able to narrow it down doing it a second time! My specs are in my sig for comparison to your hardware if you are curious. I remember the last time I reported a bug, nobody seemed to have the same issue initially, but within 6 hours it seemed everyone and their brother had it! LOL, I hope that isn't the case here, or maybe it would be for the best if they did! Good luck!
EDIT: Btw, all those samples are a LOT harder when people are shooting at you! LOL
MAME Cab PC: i7 4770@3.4Ghz (passmark 9945), 12GB RAM, Win 8.1/64, GeForce GTX645 (passmark 1898); Shiny new laptop: i7 4800MQ@2.7Ghz (passmark 8586), 16GB RAM, Win 8.1/64, GeForce GTX870M (passmark 3598); Old laptop: i5@2.3Ghz, 8GB RAM, Win 7/64, Intel 3000 graphics