When sending a fax from Word using the "Send Fax" option from the "ACT!" menu, ACT! crashes and you receive an error message.
This is a known issue. There is a work around however. Instead of using the "Send Fax" option from the "ACT!" menu, you will need to do a mail merge to the "Current Contact". In order for that to work you will need to first modify your template by adding the body of the letter etc. to your template.