Well temporarily anyway. After downloading the client and installing the patch I was unable to launch the game. The game would automatically load a black screen with a "No Signal" error displayed on my monitor. Overly frustrated by this anomaly I researched this hideous bug and resolved this error by doing the following:
1. Access - Computer/C:/Documents/Starcraft II Beta/Variables.txt.
2. Input the following variables: displaymode=0 (this will set the game to automatically launch into window mode) & frameratecap=30 or frameratecap=60.

I am newbishly using Norton Anti-virus, fortunately that was not the problem. Unfortunately this issue has only been solved for my system, it may or may not work for someone else.

On a different note, full screen windowed mode is working as well as alt-tab.

Sereiphiel,

Glad to hear you fixed it.

Can you also post some information about your computer? You can find this information in the Direct X Diagnostic Tool:

Click on Start
Click on Run
Type in: dxdiag (In Vista, type dxdiag in the search field)
Hit Enter or OK

Click on the Save All Information button at the bottom, and create a dxdiag text file, and copy and paste the first half of the dxdiag file (down to the "Sound devices" seciton) into your reply.

Sereiphiel,

Thanks for the system information!