On my Windows 7 64-bit desktop I have installed latest (64-bit) versions of both LR and PS and have no trouble in going from LR to PH for editing an initially-edited LR image.
On my Windows XP laptop, I have similarly installed both LR and PS (32-bit versions) but when I try to go from LR to PS to edit a previously-edited LR image, the image shows up in PS but none of the PS editing controls function. The PS in essence freezes at the time of transfer from LR, and I have to abort PS.
Has anyone encountered a similar problem, or have a solution to recommend?