Xline placement behaving like SNAP, but SNAP off

[lucid.balloon472536]

Hello everyone,

As the subject states, I'm having an issue with xlines.

Basically, they are behaving as if the SNAP setting is on, but SNAP is off. I don't notice this at first, but upon zooming in (way in), I notice that the line will move only in certain increments. This only occurs after I type the command and before the actual placement of the line.

I've attached an image that illustrates what I mean, with blipmode on so you can see where I clicked. I placed 6 red lines that look to be spaced equally (vertical column of blipmode points). Then I placed 3 more pink lines all snapped to the top one (horizontal blipmode points). These pink lines seem to be offset at random distances from the target line.

The yellow line on top is a current action of a horizontal xline placement. My cursor moves smoothly like normal, but the yellow line will not follow until the next increment.

I thought perhaps it was just that particular file, so I opened an unrelated file and same issue. I thought just my computer, but I observed again on multiple systems. I'm a bit OCD on making sure every point is accurate, so I'm always zooming in to this extent and fixing these minute differences.. but this is the first time I've ever noticed this. Happens on all xlines (hor, ver, ang).

Can anyone educate me on what's causing this behavior? Autocad 2006.

Thanks in advance!

Bryan