Down to what, 75%? BTW, my work machine is IE8 also, I'm not going to mess with that.
Anyway, here's what it looks like to me.
You're off by half - ALL versions of IE combined are under 50% market share now (under 40% by some estimates), but my point was that IE7 is well under 10%. You were using IE7 at the time you posted that, ergo I assumed you were only experiencing the issue on IE7. "Anomaly" is a fitting description for your picture because I haven't been able to duplicate the issue on any modern
Try clearing cookies/browser cache is really the only suggestion I've got outside of upgrading IE or using a different browser. If the guys who created SMF can't make IE7 work, I sure as hell am not going to have much of a chance.