Property Taxes - Residential/Commercial

I hope someone can help me with this information.

I just went on our Property Assessment web site, first time I've every looked at it because I was curious what our new tax assessment was going to be for 2009. I found a section that states if you operate a business from your home you have to notify the assessment office within 7 days of opening. Your property (or I imagine it is the percentage of your property that is used for the business) is then taxed at the commercial rate. It also states that if you do not do this you run the risk of being fined and could get up to 3 months in jail.

Now, I've registered my business with the municipality and have never received any notice or information on this residential/commercial property assessment.

Do any of you know anything about this?

I run my buisness from home and have been for the last 5 yrs and I'm also registered but I have never heard anything about this.