The normal reasons for this to occur are:
a) You already have a licenced copy of QODBC (v5, 4 or 3) and have downloaded QODBC v6 and are trying to use it with QuickBooks 2006. As you already have a full QODBC license for QuickBooks 2005 (or 2004, or 2003), QODBC v6 will only work to the license year you have and will not work with QuickBooks 2006. It will say the 30 day evaluation has expired and the 29 days left in this case is refering to the QODBC v6 Optimizer evaluation period left.
Resolution: You will need to purchase QODBC v6 in order to use QuickBooks 2006, (likewise you will need to purchase QODBC v7 in order to use QuickBooks 2007 and so on).
b) You are using a different country version of QuickBooks than the region you selected when you installed QODBC. For example, a couple of New Zealand users have tried the USA evaluation of QuickBooks and QODBC, and then installed the full version of the New Zealand edition of QuickBooks --- only to find that QODBC will then say it has expired.
Resolution: Reinstall QODBC using the correct region. | 
