I have ZC 1.5.0 installed in root and Authorize.net SIM is working.
I installed 1.5.3 in sub directory and Authorize.net SIM is not working. Instead of displaying authorize.net page during checkout it shows
(99) this transaction cannot be accepted

Both have exact same information in admin section.

Any idea how I can make it work on 1.5.3. in sub directory?