Greg,
No luck. Based on Jan's being able to reproduce the problem under Windows XP and Project 2010 I tried several new little test files similar to your "tea party". I included several configurations of inter-task links, duration spans from 1/2 minute to several
minutes, and links on summary lines, which is not recommended. In all cases the timescale held fast with no gaps in the displayed minutes.
I'm anxious to hear if Ismet can reproduce the problem.
Jan indicates this is not an issue of a bad Global and I would have to agree since you reinstalled Project 2010 and still have the problem, that is assuming you stuck with the default Global after the reinstall.
You indicate it may take several "tries" to make the condition occur but once it does, the problem stays. That sure points to something getting corrupted.
It has also been suggested that this may be related to screen size and indeed that may make sense if the graphics rendering engine has an issue or perhaps the PC video memory is overtaxed. These scenarios are of course well beyond the scope of this forum.
At this point I'm not sure what I can do other than to monitor this thread to see if Jan, Ismet, yourself, or perhaps some new contributor comes up with the illusive "ah ha" moment.
Sorry I couldn't bee of more assistance.
John