iMac late 2009, Intel based - External HDD Dock not seen

My internal 1TB Seagate HDD is SMART failing. I worked with support for several hours trying to diagnose, but nothing they could do except tell me to replace. Checked with Apple store, over $500!!?? I purchased a 3TB ST3000DM001, so no cooling fan problems should exist. Using a SATA USB HDD dock from StarTech.com, Model UNIDOCK2U. iMac WILL NOT SEE the device when plugged into any of the USB ports. Already tested all the ports, they work. Scoured the web and found out that maybe it was because the drive needed to NTSF first before being seen by the iMac. So I used my PC to format the drive. Still nothing. I know the dock works because the PC sees it immediately. What can I do next? I have to mirror the failing SMART drive as the journal on my DROBO has also failed and is now not being seen by the iMac. This is one big mess and I am tired of spending countless hours on stupid little problems. I know that is the nature of troubleshooting, but I need some TOP LEVEL support to solve this. Tried Option+Command+P+R on boot also, nothing. Is Woz lurking around there? Maybe he can help? Anyone, anyone? Buehler? I need to get this 1TB repaired before things start to go south on this iMac! Thanks for any help in advance.

Best,

G

PS - oh yeah, what prompted all this was when I purchased 10.8 and tried to install. It simply won't on a SMART HDD, nice move Apple. S.M.A.R.T.