@songdogtech
Well, now you're raining on my parade.
I hadn't noticed the duplicate JQuery library. I'm assuming the 2nd is Jetpack. I'll just have to get rid of the request I had originally.
At this point, until I know better, I'm just setting sites to pull in a static version of JQuery so I know it won't go and change on me. Thus, if my JS worked when I made it, better bet than relying on it remaining stable with the web's love for constant change.
As for the old-school stuff, I would love to update it. At the time, it was the only way I knew to reliably and quickly get the design to work. Relying on JS, CSS, and user's having newer browsers ... that's not an option for the audience I'm often building for. (I'm still always holding my breath when I push the envelope with all this fancy CSS 2 on the sites I build. Thank heavens for JQuery, or I'd have had to abandon all JS, since I could never make it work reliably across browsers with my knowledge level, even w/ the internet as a reference. I still often have to answer for having tried to do something "fancy" or "modern".)
I still don't know that I could build a more reliable structure today than a table for the stupid design I was handed; and not risk any given browser deciding to add its own space, or dump something down to a new line, or display nothing because there's no real content but a background-image. Not without using lots of CSS/JS/browser-specific hacks and tricks and such, which I hate.
As for changing the Doctype, not to be smart, but I did change it, and it did work. And has worked fabulously for years. If new browser versions come along and play properly with HTML, CSS, JS, etc and mess up my mojo... well, that's something else and I'll have to be utterly proper, then, with my HTML markup.
I understand that does make it hard for others to troubleshoot and to trust my design decisions aren't the issue.
So I hear you that it's more likely the theme on any given issue; but given that the only changes were sidebar images, some Javascript, and the post content, and when I see things working well on all the browsers I have access to (ignoring mobile), what with all the other frequent updates in browsers and platforms and such, there's no way I can assume even Wordpress remains viable across all platforms, esp given it's last update was in Feb or earlier (eeeeons ago).
That's why I came running here to check on issues. :)
Heck, to my point: I would think that Google AdSense would be unquestionable. It's Google! But, there it is having issues on my Android phone.
Having said that, though, I obviously must troubleshoot what you mentioned about duplicate JQuery calls and how such things possibly cause conflicts in plug-ins and other grab-n-go code; as well as the modification I made to the code Google handed out, so I could not have ads display on my test site, but also not fiddle with the code every time I jump between pasting the sidebar content in my test site and my live site.