Powered usb hub problems won't boot

Hello,
I have an XP Dell 5150, and a home-built Linux system with a Neo-4 motherboard. At practically the same time, both computers hav e started to refuse to boot with their generic usb powered hubs installed. These hubs have been installed for at least a month. The hubs are completely different looking, bought from different vendors, months apart. One, is an inline 10 port, the other a traditional 7 port. Removing hub power, and reapplying after bios boot is complete, is necessary on both machines. The failure on the Linux Neo-4 is reported as DRAM failure, (long beeps) before the bios flash screen can appear. The Dell's power on button flashes yellow periodically, and a sound like a fan blade banging is heard in unison. The Dell also never gets to light up the video to report POST codes, or anything.

Coincidence?

If I were paranoid, I might think this is a symptom of a badly executed trojan, that activated worldwide on a certain date, in all generic powered USB hubs built with cyberwarfare chips. Of course, if that were true, the web would be overloaded with reports of this problem. I don't see that, as of yet. However, very weird the problem started exactly the same time, on such different machines, with different powered hubs?!@#

Could be a glitch in the electrical supply for both the machines. That's the only CF in the equation.