Do you have Intel® Desktop Utilities installed?
Try uninstalling them, I had the very same stuttering until I've uninstalled this piece of software... Somehow IDU doesn't work on my board (I have Extreme tuning utility installed - may be they try to monitor the same and that makes a conflict).
However, try uninstalling them.
in any case - change your PSU. 400 watt is rather too low.. you neet at least 600.
I also had issues with 2053. I had a rock solid OC @5.1 (on air I might add) with 2040, however after flashing to 2053 (no change in components and returning Bios settings back to default before flash) I could not get past 4.6 without a blue screen. I flashed back to 2040 yesterday and I'm in the process of reloading all my software before I attempt to OC again. Trying to get environment back as close as possible to my original settings. I do agree with OP you do need more power, and I have had issues with Desktop Utilities in the past (X58 systems) but it was running fine for me on this board before. Good Luck, Joe
As an update... 2053 has been pulled due to obvious problems. I flashed back to 2040, reformatted and reloaded and I'm back to a 5.1 OC rock solid. I should have learned my lesson and waited for everyone else to have problems first, but 2040 was so sweet I guess I thought it could only get better. Like it says don't flash unless you think it will fix a problem your having.