No, I'm not using FileDescriptor's patch in my current 2.6.31.14 patchset.
I've sent you a few different patchsets for 2.6.31.14 over time as I was experimenting with the different manufacturer's source trees, so I'm not sure which version you actually tried.
I've removed all the old versions from my Pogoplug cloud and the latest one is linked in the message viewtopic.php?f=29&t=2472&start=10#p15007
As mentioned in my README, I'm now using the Cloud Engines patches, rebased from kernel 2.6.31.6 to kernel 2.6.31.14. Since you've reported that the basic Cloud Engines patches are stable for SATA/DMA/ethernet, that seemed to be the safest, even though it does make the kernel a bit useless on the Iomega/Silverstone/ZyXEL machines with their extra hardware.
After that I apply the more recent ZyXEL USB patches to fix some of the USB issues that people are seeing. The differences between the Cloud Engines USB patches and ZyXEL USB patches are fairly limited, but all seem to be related to fixing specific problems.
I've run multiple compilations with/without swap memory on both SATA, USB, and SATA-and-USB-at-the-same-time, pegging the CPUs at 190%+ and memory at 90%+ with no problem.
There doesn't seem to be much point in applying FileDescriptor's patch into an already-working system, but it might provide a clue as to what works better or got broken in the changes between the Cloud Engines/Iomega/Silverstone/ZyXEL kernel sources.
I'm not sure if the "hang" that you mention was in reference to FileDescriptor's patch, or to my patchset. If you've had my current patchset hang, then I'd love to know about it, preferably with any details that I could use to try to recreate the problem.