Noticed this with the latest v10 that there is a slight difference when switching between images in Library and Develop windows.
Usually a sign of a defective monitor profile.
This is what calibrators are for, but if you don't have one, replace your current profile with sRGB IEC61966-2.1 (if wide gamut use Adobe RGB). It won't be accurate, but better than a broken profile.
If that doesn't help, disable GPU in preferences. This is actually another side to the same coin. At default settings, the actual conversion into the monitor profile is executed in the GPU. With a buggy driver, that conversion may fail.
It's a calibrated (X-rite DUCS) Dell monitor and when I set the system default as suggested the problem goes away but it's not exactly a fix. Will this bug be fixed t in a future release or is it the responsibility of the calibration software developers?
"when I set the system default as suggested the problem goes away but it's not exactly a fix."
It wasn't intended to be a fix - it's diagnostic. It confirms the monitor profile is defective. You need to rerun the calibration/profiling, and double check all parameters in the software. Nothing can be done in Lightroom to correct a bad profile.
One thing to look out for is the profile policies. Set the software to produce version 2 and matrix-based profiles - not version 4 and/or LUT-based (table-based). Both the latter can sometimes be problematic in some configurations.
That said, you also need to compare at 1:1. Zoomed out, different screen resampling algorithms can cause small differences with noisy images, starry skies etc.
Thanks for the help and I'll now recalibrate with v2 +matrix and report back ( and yes I'm viewing at 1:1)
v2 and matrix gives the same result. Will try a different calibration solution ( DisplayCal)
Differences between the two modules are are expected. The reason being, Library is based on a compressed JPEG preview whereas Develop uses a rendered version of the original raw file.
Shouldn't make any difference between preview jpeg and raw in a properly color managed app like LR. Anyway I'm seeing this on processed Tiff's and jpegs.
Also I forgot to mention earlier that when I open the image in PS it matches the Library display so it's an issue with the develop display rendering.