2.8 widget operation and other issues?

Perhaps these problems are not even rooted within WordPress or due to code editing I did myself, but I am trying to track down and correct some issues through any means I can think of, so any suggestions that can be given would certainly be appreciated. I am disheartened that not even the default theme of version 2.8.2 validates when my old 2.3 that I just deleted did, and I cannot say whether this is contributory to any of the following issues.

I initially thought IE8 and/or its setting(s) were to solely to blame for the following, but the following question of mine and subsequent response were recently posted on a different forum:

Question: “I am experiencing a frustrating and confusing problem for me apparently with IE8. I have AddThis widgets (not a plug-in) added to my website (http://www.waggleweight.com/blog/), which when clicked open a separate popup window. On others’ computers their operation seems to work fine, which is the popup window(s) remaining center screen regardless of where one scrolls up or down the page. This is true even on my own computer when downloading and trying the Firefox browser. On my computer with IE8, however, the popup windows move when scrolling, only being visible when at the top of the page. When scrolling down, the popup also moves down, moving completely out of screen about a third of the way down the page. On pages where the widgets are at the bottom of the page, nothing becomes immediately visible when clicking on them. Only after clicking on them and then scrolling to the top of the page do the popups become visible, which is of course worthless if an accurate representation.

The gentleman at AddThis said it worked fine on his IE8 and another browser, it also operates fine on my daughter’s computer (also IE8) and as I mentioned before also on my computer with a different browser, but not IE8. Despite an apparent problem with only my computer, I may still have to delete the widgets if I cannot correct this problem. I have tried various IE8 browser settings in addition the default settings and also tried opening the browser with no add-ons, all to no avail. I am running Windows XP home SP3 if it makes any difference. Perhaps it is not even a browser problem, but anyone who could offer any suggestions on potential conflicts or where else I might turn to find a solution, I would appreciate that. Thank you in advance for any suggestions.”

Answer: “I tried it using IE8 under both Windows XP SP3 and Windows Vista SP2 and found that it failed miserably…it is completely hidden unless you scroll above the 1/3 mark of most articles. I also noticed a host of interesting bugs when used in other browsers, such as a login prompt being replaced by text from your blog. I do not have time to run through the Javascript code, but it appears there’s debugging to be done…”

I have also noted an inordinate number of hits to my login page recently which I initially thought might have been an intruder, but perhaps this might be explained by the second part of the answer given directly above. If none of these issues are likely to be related to WordPress functioning, then I sincerely apologize for the post. But if any of it might be related to WordPress, then I would be grateful for any suggestions on how to correct as much as possible. Thank you in advance for any suggestions.