BK - you are exactly right!
When I was (stupidly) surfing as administrator on my computer, the site had never changed, even through several IE updates.
But, today, I created a user account, and had to re-do everything in IE for that account - and LMF IS tiny! Your larger fonts were annoyingly huge in my other account's view, but they are just about right now. Strange - it's the same IE with the same settings. Everything is just itty-bitty.
Although, I've noticed FB and ebay are tiny, too....110% zoom is about right.....125% is too big, so I used a custom percentage.
I just went to Windows update to do some hefty downloads....and was admin......I noticed my zoom was at 115%. I never touched the zoom on that account....so something set the zoom at 115% (which is a custom setting, not something 'out of the box') long ago.......check your zoom on IE.....should be 115% for LMF. The zoom is right above your clock in the extreme RH lower corner (I'm sure you knew that.....).