So your pictures are starting out as 600x400, and you're then cropping a bit off one end? What size is the cropped picture before you make it bigger again? It does sound like a proportions issue.

I think what may be happening is that your cropped pictures are ending up a bit wider than your website expects them to be. And if your website is not capable of dealing with such a thing, then you are best off cropping equal amounts from both the height and width of your pictures so they stay proportional.

Alternatively, contact your webmaster and tell them to fix this issue for you.

(The blurring is due to forcing a picture to be larger than it is capable of being, yes, but if you're okay with how it looks then it's nothing to worry about. )

Thank you so much for you help Emily. I don't know what size the cropped pictures are - Paints rubbish like that it only tells me the amount of pixels. I've always cropped & uploaded successfully in Paint before though.

Now you've mentioned contacting my webmaster I'm beginning to think that maybe it is an issue with my website. I'll try uploading a cropped pic to some random directory tonight  and if that works I'll contact my webmaster - I never even considered it might be a website problem before I just thought it was me lol.

Thanks again Emily , jo xxx

If I need any new photo's added the website designer does it for me. Can you not ask him to do for you.

I've got a CMS so I can upload/delete photos myself.  I've just tried uploading cropped pictures to a directory and they went up fine, so I'm thinking its my website (it must be surely...I can't see what I'm doing wrong!) 

I've just asked my webmaster to look into it so fingers crossed it will be sorted or I'll be pointed in the right direction...