Not certain if this will help but:
1) Not new info: I too run on XP
2) Not new info, but clarifying: the experience we are describing is that the split screen display initially renders with one size font throughout, then suddenly changes as if the global font size was changed
3) NEW: Cache GCQNN3 McAbee Trailhead displays an interesting behavior - all the fonts in my splitscreen change size EXCEPT the log excerpt quoted in the description. Text begins with a smiley face and continues "December 25, 2002 by TeamAlamo" and ends at "great meeting, y'all". That paragraph of text remains the same font size even after all other text suddenly gets smaller.
1) Not new info: I too run on XP
2) Not new info, but clarifying: the experience we are describing is that the split screen display initially renders with one size font throughout, then suddenly changes as if the global font size was changed
3) NEW: Cache GCQNN3 McAbee Trailhead displays an interesting behavior - all the fonts in my splitscreen change size EXCEPT the log excerpt quoted in the description. Text begins with a smiley face and continues "December 25, 2002 by TeamAlamo" and ends at "great meeting, y'all". That paragraph of text remains the same font size even after all other text suddenly gets smaller.