When SI is perfected and when transfer is deemed to have occurred.
(i)    (e)(2)—a transfer is made (A) at the time it attaches if it is perfected at or w/in 10 days of attachment—except as provided in (c)(3)(B) if it is an enabling loan, (B) at the time of perfection if it is perfected more than 10 days after attachment or (C) immediately before the filing of the pet, if the transfer is not perfected at the later of (i) the commencement of the case or (ii) 10 days after attachment.  (This could have effect on whether transfer of SI is for antecedent debt.  Note that the important date is when there was attachment—different than (c)(3)(B) which is concerned w/ when the debtor received possession.)
(ii)    (e)(3)—A transfer is not made until the debtor has acquired right in the property.  (So, if creditor has lien on all current and after-acquired property (or accounts receivable), the transfer of the SI in the after acquired prop is not made until the debtor gets it.  If this is w/in the 90 days before b/r and it makes the creditor better off than they would have been (ie, under to over-secured), then it will be avoided if all other requirements met.)