In case you've gotten this error, look here:
There's a couple of suggestions as to how to workaround the error, but none seem too promising.
More here, plaguing Photoshop 64 bit:
The error seems limited to certain installations of 64 bit CS5 (Suites, Photoshop, Premiere Pro and After Effects) on Windows 7 x64.
Here's the solution (post 42 by nitemarebr, of this thread):
Retrieving data ...