Hello Afrodite,
Try regenerating the tables. Go to Customize -> Tables/Fields and select the Customer table. Click Finished Editing Fields to perform the regeneration. You can try the same thing on the Contacts table and Entity table. I found the tip on another post on the issue here.
Give us a call on the support line for further assistance. (1-888-925-6238 x2) We can take a brief look and see if we can help.
- Greg