Bicycle Mechanics - Noise coming from the front derailer

I am new into biking so please excuse me if I use the wrong technical term.

I have a Giant with Ultegra front and rear derailers. When I ride with the chain in the extreme positions on the front ring and rear cassette, the chain hits the front derailer and makes a clicking sound as I pedal. It only happens when I am using the a combination of the large ring in front and back or the small ring in front and back.

I have heard that this is due to the fact that I am forcing the chain to do a bit if a zig zag between the crank and rear wheel and the chain hits the fornt derailer in the process. The bike is new and I am due to take it back for the standard break in tune up, but I am one of those types that like to know how things work and can be fixed. I also don't want to break anything or wear stuff out doing thngs it was not designed for.

Is this just a simple tuning issue that the LBS can perform or should I just not use these gear combinations?

Thanks for your help

Don't use those gear combinations because it twists the chain too much. The noise that you are hearing is your chain trying to tell you that it's uncomfortable in that combination.

Big/big, small/small is a no-no. on some layouts you shouldnt even use big/big-1 or small/small+1. It all depends on how your drivetrain is layed out....plus you'll know when your in the wrong gears.

Thanks for the quick input. This is a great forum for learning stuff like this.