Designing Kitchens and Bathrooms - bathroom grout problem

We renovated a bath six months ago. There is cracking in the grout where the wall tiles meet the floor tiles, in corners between wall tiles, where wood door frames meet up with floor tile, and where a built-in wood cabinet is up against wall tile. What is the proper material to use in each of these places? I assume that a chalk is necessay whereever wood meets tile ? Does the cracked grout have to be removed before new grout is applied, or can grout be patched over? Should chalking be used instead of grout where wall and floor tiles meet? I want to understand this before the contractor comes back to fix it all so that it is done right this time and we don't have further problems.
Help! Thanks. sdnv@msn.com

Have the contractor scratch out all the cracked grout and replace it with caulking. Grout cracks when there is movement. Caulking moves or flexes.

John

http://www.johnbridge.com