Noncritical bug found in class TaxSpec in Dynamics AX2009 SP1.
The method taxExemptDescription uses a returntype of Description ( 60 char), but returned variable is of type Memo / Notes.
You’ll will always get the first 60 character of the defined text.

Description taxExemptDescription()
{
return taxExemptDescription;
}

change to:

Notes taxExemptDescription()
{
return taxExemptDescription;
}

and the same in the classdeclaration for the variable taxExemptDescription.