Ok guys, I am seriously in need of help here and this system is driving me crazy!
I bought two graphics cards (one 2GB EVGA GeForce GT 610 and the second one is an 1GB EVGA GeForce 8400GS..With both, I am encountering the same problem (spinning pinwheel) at the second screen as before. By the way, this time I tried unifail. Maybe that's why I am getting this error. I will try with myhack and see if it produces different results.
Edit: Great Success!
Here goes. This might be helpful for someone who has a small form factor Dell Optiplex 9010. I inserted the EVGA 8400GS, prepared myhack installer and installed as directed. Since I was using an nvidia graphics card, I had to type GraphicsEnabler=Yes, otherwise the system would go to power save mode immediately after the apple logo screen. Anyway, the installation didn't fail - it actually said succeeded. The mistake I made was to use the patch presented by the OP (I didn't need this because I wasn't using the built in Intel GPU). So, this is what I did - I plugged in the flash drive with myhackinstaller again and ran myhack from it and this time, I said install extras, but used the generic one. That's it. After that, I crossed my fingers and booted the system with GraphicsEnabler = Yes and it was a grand success!
After installation, I ran multifail (chameleon, stolen and rebranded) and only installed the ethernet drivers and voodooHD 2.8.4 drivers. So, pretty much everything works well now.
I can't thank you guys enough - all of you have been great and I couldn't have installed this without the helpful feedback I got from everyone here. Of course, patience is key and willingness to experiment.
Over the weekend, I will try this with the 2GB GeForce GT610 card as well (since OSX Mavericks has built in support for 6xx cards). I'll post an update on that sometime on Sunday if everything goes well.
One question that remains is how do I circumvent entering GraphicsEnabler=Yes every time I boot? Thanks in advance.