Martin,
If you quit PM, launch it again and immediately show the same image side by side and then press Z to zoom into 100% view does the problem happen? Or does this problem happen over time?
I still have the problem even after a machine restart. The behaviour however seems to depend on the size of the preview window. At times the images are correctly zoomed at 100%. But changing the size of the preview window by very slowly dragging a corner of the main window causes the right-hand image to jump to a smaller size. Continuing to drag causes the image to jump between these two states. It is very sensitive to small changes in the window size. If I get it right - and don't change the window size then it seems stable - so this is a workaround at present.
It sounds like PM is running low on memory. Run the Activity Monitor application (it's in your Applications/Utilities folder) and find Photo Mechanic in the list. See how much memory it is using when the problem occurs.
What are your Memory Cache settings? (Preferences->Caching)
I attach a screenshot. 512MB looks a bit small. I have increased it to 1024MB but this does not seem to have changed any thing.
I suspect, Kirk, if you cannot easily reproduce it - and no-one else has reported it then the issue is probably at my end. I'll investigate a bit further. It's not actually urgent and I have a workaround. Enjoy a well deserved Easter break.[/quote]
The 512MB you have is for your Disk Cache. The Memory Cache is below, and more is not always better. Let's leave things alone for now.
I'd like to see if PM has a memory leak issue on your system so see what you can find out from the Activity Monitor and report back when you can.
Thanks,
-Kirk