Time machine gets stuck!

Running OS 10.7.4 2.16 GHz Intel Core 2 Duo

I just installed a 750 GB 7200 RPM hard drive with success. I backed it up ONCE to a 500 GB hard drive (approx 356 GB of data). The second time I attempted to backup, the hard drive stated that it needed more space. No problem! I have a FIREWIRE hard drive (1TB). I erase the external drive and begin the backup process. It starts out at a great pace, looks to be about 7 hours worth of work. Great! I'm heading to bed anyway. In the morning, it is stuck at 4.24 GB and tells me that the process will take another 8 days! NO WAY! CANCEL.

I go to these forums and the most obvious solution is to restart the comptuer. Sounds like a plan. Done.

Again, seemingly stuck at 4.24 GB. So I begin watching the number of items to move. 842,444 left. However, in a few minutes, it has changed to a lower number. So---we know we're not truthfully stuck--just really going slow for some reason. Depart the house for the Apple Store (backup still processing).

Talk to Apple Tech who suggests that it could be the actual FireWire Drive OR the connection. Thought I'd buy a Time Capsule, but all they carry are the 2TB for approximately $300.00. Nope!

Go back home and just let it continue. This morning, we're up to 19GB. HOWEVER, as a church musician, I needed my computer. And the FireWire drive requires external AC poower. So, back to the forrum. Can it be paused? The general consent was "yes" if you just dismount the volume.

Back to the house today after church to reconnect (hoping that it would resume where it left off....NOT). Now the process time says 1325 days until completion. I just giggled and went to take a nap. Two hours later, only 55 MB transfered. SHUT DOWN and sigh.

Back to the Apple Store to buy a 2.0 USB 1T external drive. IT MUST BE THE DRIVE, right?? $164 contributed towards the cause.

Back home. Restart computer. Connect new hard drive. Very fast back-up speed. YES!!! Fifteen minutes later, I go to check the progress. 4.24 GB and crawling!! NOOOOOO!!!!!

So, now we're up to two more days calculated time.

Please tell me there is a fix for this??

(It took less time to clone the drive --- which is my next step.)