Curse client problems

I use the 3.0 client because I can't get the damn 4.0 one to install or work on my system. I've tried installing/running as admin countless times, when it does install, gets to the login, then keeps giving me errors when trying to log in, and yes, login/pass are right. I use the 3.0 client and no problems, till this week. The past few days since 4.2 came out I've noticed it's not wanting to install the new updates for my addons. At first, it was just Recount, DBM, and Instance Lockout, now it's doing it for more addons. Keeps telling me that it fails to install the update. I've even tried to uninstall then reinstall the addons, updated versions and still fails to install. I even tried to reinstall the 4.0 client and keeps giving me the same old problems on installation/login. I got it past the firewall/server check list, but still won't accept my login/password. Was wondering if anyone else is having any problems with this. And no, I'm not a premium user, I use the free version. Don't see the point in paying to update my whole list at once if I can still do them one by one. The extra time don't phase me none. I'm on Vista 64bit and have can't find any other .exe files to download and install other than the main one through the site under the client tab.

I would try to uninstall 4.0, then maybe uninstall 3.0. Reboot machine. Play for a day, reboot again. Then install 4.0. If you still can't get 4.0 to run then google curse client or check if they have forums. I am pretty sure they have a help section, either in forums, or as a FAQ. In other words, aim to get 4.0 to work more than fight to get 3.0 to work.