🚀 go-pugleaf

I have no problems viewing pdf's normally. But if I am on a secure page (https://), the pdf won't load. This happens on two different web sites, both the Cox cable site and USAA insurance, I am unable to view my statements which are in pdf. I can get around it on the USAA site by choosing to save the pdf instead, and then viewing it locally, but the Cox site doesn't give me that option. I pick a statement month, then it opens up a new tab and goes to a secure page where it appears to try to download the pdf statement- to then try to display in the browser window, I guess? At any rate, there is a little download icon down in the left corner of the status bar, but the progress bar never completes. It just fizzles out and I'm left with a blank page. I had these problems when I used XP Home Edition and nothing has changed under Vista Home Basic. Interestingly, I have no problem viewing my statements on either site from my work computer, which uses XP Pro. I was running Reader 8 on my home system and just recently upgraded to 9, but with no change with this problem. At work Reader 7 is installed.
So it would appear to be a setting on my computer, a limitation of the low-end OS's, or some difference between Reader 7 and 8/9. I am mystified as to exactly what it could be, however. Anyone have any experience with this issue?