2. "Double Debtor Problem." This section addresses the "double debtor" problem, which arises when a debtor acquires property that is subject to a security interest created by another debtor.

3. Taking Subject to Perfected Security Interest. Consider the following scenario:

Example 1: A owns an item of equipment subject to a perfected security interest in favor of SPA. A sells the equipment to B, not in the ordinary course of business. B acquires its interest subject to SPA's security interest. See Sections 9-201, 9- 315(a)(1). [Maine cite section 9-1201, section 9-1315, subsection (1), paragraph (a)] Under this section, if B creates a security interest in the equipment in favor of SPB, SPB's security interest is subordinate to SPA's security interest, even if SPB filed against B before SPA filed against A, and even if SPB took a purchase-money security interest. Normally, SPB could have investigated the source of the equipment and discovered SPA's filing before making an advance against the equipment, whereas SPA had no reason to search the filings against someone other than its debtor, A.

4. Taking Subject to Unperfected Security Interest. This section applies only if the security interest in the transferred collateral was perfected when the transferee acquired the collateral. See subsection (a)(2). [Maine cite subsection (1), paragraph (b)] If this condition is not met, then the normal priority rules apply.

Example 2: A owns an item of equipment subject to an unperfected security interest in favor of SP-A. A sells the equipment to B, who gives value and takes delivery of the equipment without knowledge of the security interest. B takes free of the security interest. See Section 9-317(b). [Maine cite section 9-1317, subsection (2)] If B then creates a security interest in favor of SPB, no priority issue arises; SPB has the only security interest in the equipment.

Example 3: The facts are as in Example 2, except that B knows of SPA's security interest and therefore takes the equipment subject to it. If B creates a security interest in the equipment in favor of SPB, this section does not determine the relative priority of the security interests. Rather, the normal priority rules govern. If SP-B perfects its security interest, then, under Section 9-322(a)(2) [Maine cite section 9-1322, subsection (1), paragraph (b)], SPA's unperfected security interest will be junior to SPB's perfected security interest.