I found a small bug in the Authorize.net AIM API PHP SDK (which is included in the GravityForms Authorize.net Add-on) related to eChecks. I know GF does not actually provide eCheck functionality, but i'm working on a custom implementation.
In plugins/gravityformsauthorizenet/api/lib/AuthorizeNetAIM.php, line 290 uses the wrong php variable:
'bank_acct_name' => $bank_acct_type,
'bank_acct_name' => $bank_acct_name,
This bug causes the AuthNet Merchant Interface to display "CHECKING" (the bank_acct_type) in the field intended for bank_acct_name. Maybe not a big deal, but could cause problems for merchants.