If date format is changed in the shop admin / configuration from %m/%d/%y to %d/%m/%y
Then the following error occurs when trying to add a new tax rate calculation (under products)
DateTime::__construct() [datetime.--construct]: Failed to parse time string (19/10/11) at position 0 (1): Unexpected character
Joomla Version 1.7.2
Virtuemart 2.0.0-RC-2i
I had the same error message...but with editing gift coupons.
Manch