Hey guys, first post here. I found this forum while trying to find out a solution to get Eyefinity working on my setup. I wanted to post in this thread because I have had success with the same Displayport->VGA Adapter in the OP.
This is the one I ordered from eBay, it's similar to the one in the OP and more than likely the same manufacturer.
http://cgi.ebay.com/NEW-DisplayPort-Display-Port-Male-To-VGA-Female-Adapter_W0QQitemZ160418857721QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item2559b582f9#ht_1185wt_939
Some tips and tricks on the situation that I encountered when trying to initially set up Eyefinity:
-First, my basic set up (if anyone finds it pertinent)
*ASUS M4A785T-M/CSM motherboard
*AMD Phenom II X4 2.60ghz processor
*XFX Radeon HD5770 GPU (the batmobile version lol)
*Mod Xtreme-Pro 500W PSU
*3GB RAM
*Windows 7 32-bit
*3 x Acer X233h 23" screens 1920x1080
-Before getting my adapter, I was already running three monitors, two connected via DVI to the card and the third connected to the onboard card via VGA.
-Upon installing the adapter on the middle monitor, CCC was able to detect the monitor reading it as a Displayport monitor. It stayed at the current settings, three split up monitors with the desktop being the left monitor with no changes to resolution on any of the screens.
-The first time I tried to follow the steps to setting up the Eyefinity group, I had set up the group from the left monitor which was connected as DVI. I was given a very long series of screen blackout for about a minute before CCC came back on. When it did, CCC presented an error about the Displayport link being faulty or something like that. It kept the Displayport monitor in 640x480 resolution with no option to change. The right monitor was disabled, and the left monitor was left in 1920x1080. Upon trying to play with the settings, sometimes only the primary display would stay up and the two others were put into standby. Other times it would duplicate all monitors in 640x480. This was just from fiddling with the display options.
-Without unplugging and replugging anything, I saw another member who posted here earlier about making sure the Displayport monitor is made the primary when setting up a new group for Eyefinity. Following those instructions yielded the successful result. The Displayport monitor is set as primary, and following the steps laid out in CCC, you're able to adjust for bezels/etc.
-One thing to note; I wanted to set up Eyefinity as a profile instead of just running it all the time. Hydragrid would not work with me, especially since for some reason the hotkeys for it don't work with any windows I open. I like the three split monitors when I'm running non-gaming programs and that way it's easier to maximize windows to the screens instead of using Hydragrid. When I try to save that profile and switch from Eyefinity to the three split displays, the displays are all out of order. It may have something to do with which monitor is the Displayport monitor. At this time I still have it plugged into the middle screen, and I'm hoping making the left monitor the Displayport will resolve that.
-Final note. This has worked with my setup, but unfortunately I don't have any other setups to test it on so I can't say it'll work for everyone (i.e. different monitor sizes/resolutions/computer specs). For $17, it was a drop in the bucket compared to what I've spent getting back into computers/computer gaming (Eyefinity looked so cool I had to ditch my laptop for it).
I was able to play Battlefield: Bad Company 2 for about an hour at "medium" settings without any flickering or shutdowns. FPS is not as good but I figure I'm pushing the little 5770 to the max.
Here are some pics, sorry for the poor quality I was just excited that I could get it working lol