What you will see
Two-sided or duplex printing results in a last page that is disproportionate or compressed in size when compared to previous printed pages.
Affected products
This issue was first seen on the MX511de MFP; however, printers with similar firmware architecture and a polygon printhead may exhibit this issue.
Suggested remedy
If you have recently upgraded your printer firmware to LW60.##.P630, or LW60.##.P632, then revert the printer's firmware level back to LW50.##.P543 or LW50.##.P589 to address this issue.
Perform these preliminary procedures:

Verify firmware level is at LW60.##.P630 or LW60.##.P632.
Steps | From Control Panel and Menu's Setting page: | From printer's embedded web server (EWS): |
1 | Press the Menu button on the Operator Panel. | 1. Launch your Internet browser application. |
2 | Touch Reports. | 2. After http://, enter the printer's IP address. |
3 | Touch Menu Settings Page to start printing. | 3. Click on Reports. |
4 | Look for the code level under “Device Information”. | 4. Click on Device Information and identify the value next to Base=. |

Verify your printer is utilizing a polygon printhead by looking for the black dot on the printer's label.
See sample image here.

Contact Lexmark Technical Support, reference this article ID# SO7869, and request back-level LW50.##.P589 firmware for testing purposes. You may also inquire about any new EC6 versions of PE firmware that corrects this issue.
Explanation
This performance issue was addressed with a previous EC5 PE-release level of firmware. The schedule required for regression testing, and the time required for planning EC6 .P632/.P633, prevented the inclusion of this fix.
NOTE: When calling for support, you will need to provide your printer model/machine type and serial number (SN). Please be near the products described in this article to expedite the support process and reduce call-back situations.
LEGACY ID: SO7869
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