Thanks for your response. I definitely unplugged everything (except keyboard and mouse). No blue screens, only what I listed in my original post. This is the fourth different Hub that I've tried, and it works fine once I get past Startup.
For now, as a work-around I've rigged an On/Off switch to turn power off to the Hub before I start the computer each time, then turn it on when Startup is almost complete. So far no problems.
I hope that Alienware/Dell can ultimately come up with a permanent fix.