I found an error while editing a large .jpg this morning. I am using the latest 3.5.10 on windows 7 SP1 64bit.
image details:
17.5mb file size
6300 x 7875 pixels
150 dpi
24 bit color depth
These are my steps:
I had a JPG photo open
pasted another image from the clipboard into a new layer
placed the layer where I wanted it
resized the layer
clicked flatten image from the menu
tried to draw on the image using the pen tool where the "new" layer was drawing onto the original image (remember its flattened now, so there is only 1 layer) but the pen tool stopped writing when it hit the end of the "new" layer
Steps I took to verify and resolve:
Clicked undo on step 6 to remove my line i drew
Saved image as JPG
Reopened saved image
Used pen tool to attempt to draw again and it worked as expected.