Problems With Desktop Computer BIOS Booting When External Hard Drive Is Connected To Front 2.0 USB Port. ...Why? ...Reason? ...Fix?

Issue: Hello. I have a custom-made desktop computer that has the ASUS P5Q (regular model version with the most PCI port connectors in the P5Q series) motherboard (already 3 years old now). I have had issues with connecting my Seagate FreeAgent Desk 1 TB 2.0 USB external hard drive cable connection when connecting to either of my two desktop tower’s front panel’s 2.0 USB ports. What happens when I connect this external hard drive’s USB cable to the one of the two front panel’s 2.0 USB ports FIRST BEFORE powering up the desktop computer, the initial BIOS screen that normally quickly flashes before me, will hang indefinitely on the initial BIOS screen. When I unplug it, sometimes, but not always; the BIOS will proceed on with the booting process and then on to the startup of my Windows 7 64-bit operating system.

NOTE:

1. The Seagate FreeAgent Desk 1 TB 2.0 USB external hard drive has a separate power source that uses a power adapter that is plugged into the power source outlet prior to powering up the desktop computer too.

2. The desktop tower’s front panel’s 2.0 USB ports are connected via cable to one of the ASUS P5Q’s (motherboard’s) 2.0 USB connectors internally inside the computer tower.      

Now, I also have installed separately a 4 port USB 2.0 PCI card into my motherboard where I can attach any 2.0 USB hardware’s cable into one of the 2.0 USB ports located on the BACK of my desktop tower. Now, when I connect this same 2.0 USB cable from this same Seagate external hard drive instead into any one of the 4 port USB 2.0 PCI ports FIRST BEFORE powering up the desktop computer, the initial BIOS screen WILL flash before me while the BIOS completes and the Windows operating system will boot successfully without any hesitation. The process of BIOS/system start is fine when I use any one of the 4 port USB 2.0 PCI ports on the BACK of my desktop tower.    

Question:

1. Why am I having problems with my desktop computer BIOS booting when connecting my Seagate FreeAgent Desk 1 TB 2.0 USB external hard drive to any one of my desktop computer’s tower’s FRONT panel’s 2.0 USB ports and NOT when connecting with any one of my 4 2.0 USB ports located on the BACK on my desktop computer’s tower when I initially boot my computer’s BIOS?

2. What is the reason for this?

3. How can I still use my desktop computer’s tower’s FRONT panel’s 2.0 USB ports too without any issues like my BIOS freezing up?

Thanks!