At least part of the problem seems to have been my computer. Finally convinced my dh to actually physically come over and look at my computer. To make a long story short, he finally determined that something in the background was eating up my CPU and I was getting millions of page faults. Once he logged on as administrator, he was able to see what was hogging up the machine and eliminate the programs. Once he did that, I stopped having problems getting on and staying on the QB.
My computer is an older one and likely had the CPU problem before we changed internet providers. However, I still think there is something about the new QB that interacts with other conditions to create a timing issue. I'm not a computer techie at all, but my personal guess is that the new QB is very data rich compared to other sites I visit, which means that my computer has a lot more information to load for every page. Before we changed providers, perhaps the slowness of the data transfer rate was pretty much in line with my hogged-up CPU, so they could work together to access the QB. Once our data transfer rate became very fast, my hogged-up CPU couldn't keep up with the data coming in. My theory, anyway. Dh would probably laugh.....
Anyway, I am HAPPY to be able to stay here consistently again. If someone else tries to clean up their CPU, just be careful because you can trash your computer if you delete the wrong files (at least, that's what dh told me as I watched him delete files off my system). We still don't know what caused the excess files, but dh thinks it might be a corrupt Internet Explorer, as there were many more copies running than I had windows open.
Hope this helps someone......