Can you see what I mean by the line on the corners looks thicker and uneven?
It is driving me crazy and have tried Photoshop Live and that makes matters worse. Would you also mind telling me where I can find the 'pop up window' that so many posts mention so that I can enter the exact corner radius?
Many thanks again, Pete
Your canvas is too small. The width of the lines on top/bottom and sides is being cut off. That's why they look narrower.
Use Modify>Canvas>Fit Canvas, or simply enlarge your canvas by two pixels in each dimension, centered.
Thanks again, this with the other answer you gave has solved this problem.
Happy to help! I'm glad you got the result you wanted.