When using either the 16bit or 32bit Polymost renderer, some of the doors in E2M8 have stray black, vertical lines in the opening. This happens in both open doorways and doors that need to be opened. In the latter case, you can also see the lines on the closed door, although you have to be looking for them. They appear in both full screen and windowed mode, no matter what the resolution.
The lines don't appear when using the 8bit classic or 8bit Polymost modes
Also, I noticed that there are black lines in the corners of the doorway which aren't there in the 8bit modes. I only mention this because it seems connected to the other lines.