A: Hi Rex, I can never say no to a loyal fan so let me try to help even though my response may not be what you want to hear.

First off even though a toilet replacement looks easy on paper, in real life it's normal to run into problems. For instance, broken flanges, rotted floors and uneven floors are very common road blocks that plumbers face on a regular basis.

The good news is that an uneven floor is the easiest of the three that I mentioned to work around. With any toilet the area under the toilet does tend to get moist and hold water so it's important that the materials used under a toilet are waterproof.

Ceramic tile is an excellent material for a toilet to sit on, bare plywood is not. The plywood can hold moisture and may start to rot, harbor bugs and promote mold over the long haul. I recommend that you remove the plywood base and put the toilet back on to your tile floor.

OK, now lets address the rocking issue. See where the toilet is rocking and find any low spots on the floor around the toilet before you tighten the closet bolts.

Most home centers sell special plastic shims approved for toilet use that can be set into place with a dab of caulking. These shims should give you a good base and cut back the rocking. Once in place, gently tighten down the closet bolts to lock the toilet into place.

Most plumbers agree that caulking should not be used around the entire toilet base, only at the shim points. This will promote air flow under the toilet and if the flange seal ever leaks the water will be noticed around the base of the bowl.

A completely caulked toilet base may hold the water under the toilet and if you ever have to replace the toilet, the caulking may pull up the tiles or base floor.

Sorry Rex, but you asked for it and now it looks like you have to do the job over. I hope you're still a loyal fan!