Good for you. You know as I was reading this I found a link to question that I kept a file of as this too may also cause some PCI-E card issues as I just had a card stop working for me and once I used the Rosewill RC-401-EX ($14.00); which by the way is the SAME EXACT card as the 2 Sonnet ones that I purchased ($39.00), right down to the very circuits and board config. In any case here is what was said by this person:
Question:
Why won't my computer boot up after installing your PCI network adapter?
Answer:
The reason could be that your computer is experiencing an IRQ (Interrupt Request) conflict, meaning,
after the network adapter was physically installed in your computer it may have been assigned an IRQ
that was already in use by another device. PCI cards can share IRQs for the most part, however,
network adapters usually cause conflicts when sharing IRQs with other devices.
The network adapter and the other device both try to get the attention or "interrupt" the processor (CPU)
at the same time. This "confuses" the processor, and may cause it to lock up (freeze) or keep the
computer from booting all the way up.
The simplest way to try to fix this problem is to shut down your computer, unplug the power cord and
move the network adapter to a different, available slot inside your computer.
Reconnect the power cable to your computer and restart.
Rosewill.com - Computer Case, Power Supply, Computer Accessories, Networking, Peripherals. Price, Quality, and Services.
Again, this is obviously not your issue, but it does show how sensitive some system setups are when it comes to using different products... nothing's perfect... I'm glad that your issue (for now) is fixed...