Charlie,
Most players do not play in full screen. The only way to play in full screen prior to the update 2 days was by using the F11 button and most players do not know that exists. Full screen mode in your browser is different then full screen mode in the flash player. Hitting F11 makes the browser take over full screen responsibility. Using the button in the interface makes the Flash Player take over full responsibility. It is entirely possible to have issues with the Flash full screen mode and not have issues with the browser full screen. My low-end PC has flash full screen issues, but no F11 full screen issues.
If the update was causing a problem then it would be a universal problem experienced by all users. If the error was in fact on our end then it's not possible for some users to be experiencing a problem and other users not to be. Not while everyone is executing the same code, it just can't happen. I have two PCs with entirely different setups. One is low-end (this one) and the other is higher-end and neither is experiencing the problem you are describing. If there was a problem with the update then both PC's would see it. My low-end PC has it's fair share of issues, but I also know that it is my PC and my hardware that is causing it. I know this is true because I have another PC to compare it to.
I'm sorry that you think we're lying and that you don't like to hear that the problem is local to your machine, but if instead you would try to work with us (perhaps by sending an email and asking someone to help you look over the problem) then we might be able to help with figuring out what's causing the issue for you. Continuing to assert that things are wrong on our side when all of the evidence is suggesting otherwise is only going to make for a frustrating experience for you.
I'd recommend sending an email to members@worldgolftour.com. Explain the situation, your PC setup and what's going on as clearly and concisely as possible. I'm sure they'll be happy to try and help figure things out for you, but if you don't at least make an attempt to get help then your frustration may never go away.
That's the best advice I can offer and I hope you at least consider it. I'm sorry that you are experiencing an issue with the game. We will try to help you if you are interested.