In Bulgaria it is common practice to put the tax evaluation of the property on the title deed. This value is set by the local municipality and is generally less than 20% of the value of the property. It's just a tax avoidance measure. This has worked fine in the past for the local market as all transactions put the lower value so you never got stung for capital gains tax. However, the rules in Bulgaria are changing. Tax evaluation prices will increase by at least 100% this year and will continue to increase until they match up with the actual value of the property.
Example:
I buy a house for 100,000 in 2004 and put 20,000 on the deed. I only pay 3% taxes on the 20,000 - good news so far.
I try to sell the house in 2008 for 200,000. Bulgaria laws have changed so the real value is put on the property deed. I end up paying CGT on 180,000 (200,000 less 20,000 price that is on the deed) instead of 100,000.
Solicitors sometimes will tell you about this practice but sometimes they won't as it was quite common practice in the past.