Why are my browsers displaying MyGrandRV in a simple and ugly vBulletin list?

[boyscout]

First, a month or two ago, my Firefox browser began displaying MyGrandRV in a highly-simplified and ugly format with a vBulletin logo at top left I didn't think I did anything to make the change so I wrote it off as another quirk of Firefox and began using Chrome here.

Earlier this morning I visited with Chrome, wrote a post, checked settings and cleared all thread subscriptions but - AFAIK - did not make any other change. Upon my return, Chrome now displays the ugly vBulletin presentation.

I've just logged on with Internet Explorer and the site looks the way it should. For now!!

What's happening?

Thx.

EDIT: Damn, now I've returned with Chrome and it looks fine. I did have to log in, which I normally don't have to do because the site is "remembered" in my browser.