I can't tell what it is that you are talking about from the screen capture. Please post a shot of the ID file as well, and it would gelp if you would point out where the problem is.
Does it change in Acrobat if you zoom in or out?
And I can't quite tell -- is the magenta line at the bottom of the page in the first ID shot the botom margin guide, or something else? It's extending across the two columns, but I'm not seeing any indication of column guides, so I suspect there's only one column on the page and you've done the division without guides. Is that correct?
It doesn't change when I zoom on or out.
The magenta line on the first ID shot is the bottom margin guide, right. And yes I divided the page without any columns.
On the second ID sho you see the "preview" without any margine or guiding lines.
It sounds like it may be a display artifact since you say it doesn't change when you zoom (perhaps I worded that badly -- does the relative weight change, i.e, does it get thicker on screen as you zoom in the way a drawn line would, or does it stay the same weight?)
IF you go into the Acrobat Prefs and turn off Enhance Thin Lines and Smoothing, does it go away?
One thing I noticed right away is the bullets appear to be at the left edge of the yellow text frames in your InDesign file but are inset from the edge of the yellow boxes in the PDF.
Correct me if I'm wrong, but it appears you have the text frames with the bullets set with a yellow fill and the frame set with a drop shadow and this is placed above another frame that is also yellow.
Does the lower yellow box have a stroke around it? If so, that is the problem. Also, hard to tell but maybe the drop shadow is also affecting the appearance of the stroke.
I'm not sure of the effect you are trying for, but you can just delete the lower yellow boxes and increase the size of your text frames and leave the drop shadow intact.
But, you need to put an INSET value for your text frame to keep the bullets away from the left edge and also keep the text away from the right edge of the text frame.
To do this just select your text frame, go to the OBJECT menu and select TEXT FRAME OPTIONS.