Well after 3 days, 5 windows 7 mbr repairs and at least 10 reinstalls I finally got Mint 12 installed on it's own external usb 3.0 seagate hard drive and it boots like it should.

it appears that a lot of people are getting this grub recovery> error along with something about file system not being reconized. Most people have been saying to reinstall grub2 by way of chroot and a live cd. Well i managed to not to do that.

First my system is an MSI GT660R laptop. Very well equiped. 6 gig memory (DDR 3), intel i7 quad, geforce gtx285m video card, 2 500 gig hard drives on a raid 0. Recently I got a Seagate 1 TB USB 3.0 external hard disk drive for a fresh install of linux mint 12. Was trying for Ubuntu 11.10 but had simular issues with grub rescue>.

My final attempt finally worked, here is what I did to get this config to work.

1) Prep: I should have unplugged my internal hdd but did not. I have much experience in this type of install. I do know that one mess up and it to the "AAAAhhhhh poooooh" comment. Replace pooh with a word that works best for you. Anyhow I got a copy of the cd version of mint 12 x64. Did the usual stuff.

2) Booted live cd to desktop and played around a bit before i did the install. This was to see If i would enjoy the new installment. Once I was ready I wen through the install process.

3) Once I got to the partition screen I had to pay close attention to the drive I was working with. This was rather easy since it was the only drive on the system that is one tb. I broke the drive into 3 main partitions. /swap (12 gigs, a bit big, hey I got the space for it) / (100 gig) and /home (all left over space). Next at the bottom of the window I selected to install the MBR to sdc which is my install drive. I double checked it in the partition layout screen just to make sure.

4) Finally I completed the rest of my install as normal.

Now I have a portable linux mint 12 hard disk that I can use when ever I want instead of win7. I did this because linux was running really slow when openshot was running in a virtual environment. Lets see if the speed is improved.

USB 2.0?
3.0?

I installed to a USB pen.
USB 2.0, at 480Mbps... seemed doggedly slow compared to same O/S installed to SATA drive

My USB 3.0 does not boot external drives so I am on a USB 3.0 disk drive connected to 2.0. Withusb thumb drives you should be using unetbootin for Ubuntu based systems. Doing a standard install with swap will burn your drive out way early due to limited read/write cycles. Also this could speed up your access times, but then again it may not. When running this type of install the package you want to run will have to decompress then load to ram prior to actually running.
I have been able to encode 250 frames of video in about 10 minutes. I am using openshot. As my video editor. I also have inkscape and blender installed as extra features for openshot. This package has crashed once or twice since I installed it.

I have noticed a slight degradation in internet speeds while using cell phone tethering on 3g. Not sure if this helps, let me know and I can try and assist when I can.