I've had this problem before in LR 1.0 but now again in the latest version. I've searched the Adobe site and found one reference to this perhaps being caused by a corrupt monitor profile so redid my NEC2690 profile with SV - the problem persists.
Randomly I've had several images (viewed from LR in any module) that appear fine suddenly develop a solid yellow bar running across half of the image. Very disturbing as you might imagine!
I've thought this must be something in the LR database and so have done the following with no avail:
1. I've reloaded and tested the integrity of the database - problem persists
2. I've copied the raw file to elsewhere, renamed it, deleted the file in LR and then reimported the copied file. It immediately develops the yellow bar....
Anyone else seen this and any idea on fixes!!??