One of the adm guys said that cache could be cleared by holding the topic buttons simutaneously while game is loading. Anybody know any other tricks for 360 like this one. Is there a combo that will let me actually play the game?

Different games have different methods for clearing the cache.

With this game its LB + RB + X while booting the game

Other games may have different methods.

Although if you are not sure if the game has it's own cache clear method you can just clear the system cache by going to the memory section of the dashboard, pressing Y then select clear system cache. This method will also delete patches as well as the game cache. Patches will redownload automatically when game is booted up.