Solution:

Some of diagnostic programs don't really test the IRQ of LPT ports by themself. They just dectect if there is/are printer ports in the system. If there is/are printer ports in the system, the diagnostic programs will "guess" where the IRQ's of the printer ports are (In general, the IRQ's of printer ports are IRQ 5 or 7) and then test the proposed IRQ (eg. qaplus 5.20, MSD, AMIDIAG 5.11E, ...etc). For POS-460, the IRQ of its LPT1 is 5 or 7. That meet diagnositc programs' guess, but the IRQ of its LPT2 is 10, 12 or 15 (hardware setting). That will make some diagnostic programs guess wrong and get incorrect results. We have found some diagnostic programs which don't guess the IRQ of LPT ports, but test every IRQ for any devices (including printer port). The QAplus 5.29 is one of them. After trying it, you will see the correct IRQ of LPT 2. (ps. you need to plug a LPT loopback connector into LPT2)