OK, I just worked it out (I Hope!). When I disabled the nedstat/webstats4u code by “commenting it out” in the footer template, the popups disappeared in my browser. Unfortunately, it would appear that Internet Explorer doesn’t understand HTML comments and tries to render them instead. It finally occured to me when I saw “–>” appearing next to the webstats4u icon in IE, that I had been so excited about getting rid of the popups that I only commented out that section of code, and forgot to remove it.
This appears to be a rendering bug (or feature) of Internet Explorer, that the standard “< --" and "-->” comment code is not treated as a comment, and instead treated as renderable code, which is why the popups continued to appear in Internet Explorer.
It should now be fixed (although a hard refresh using CTRL-F5 of the samuelgordonstewart.com homepage should force it). Again sorry about the inconvenience, I just never counted on that basic staple of usefulness being ignored by a browser.
Hopefully Internet Explorer will understand comments in version 7, but I’m not holding my breath on that one.