Here's what I did to make mine work.....and it works like a dream.....no editing needed of EDID.
Download the 10.3 beta.
Remove your current Catalyst driver in add/remove
Restart in SafeMode
Go into My Computer and remove any files you can find that have anything to do with ATI.
Now run DriverCleaner a couple of times.
Restart and install the 10.3 Preview, you should get the bezel compensation pop-up just after you create the EyeFinity group profile.
I have two Dell 2408 and one Dell 2410 and am using W7 Professional x64.
I exactly did this way to install official 10.3 (using DriverSweeper) and still no have bezel management (see my sig for hardware details) and others problems with games...
After a couple of tests and benchmarks, i decide to revert to 10.2.
So disappointed, bezel management is one of great feature that i'm waiting for.
If someone could help, thanks in advance...