Store URL: http://www.reallywildflowers.co.uk/
WordPress version: 3.8.1
WP e-Commerce version: 188.8.131.52
Gold Cart version: 2.9.7
Theme: Child theme of Twenty Twelve
I've added an image to each category. A day or so later the images are blurry. I re-uploaded the images and all is fine. A day later and the images are blurry again.
I then looked at the file name via Chrome's Inspect Element. The file name is wildflower-collections-250.JPG, which is correct. When the image quality goes blurring the file name changes to wildflower-collections-250-64x64.jpg, which is 64px by 64px. Where did this thumbnail size come from? 64 x 64 doesn't appear anywhere in admin dashboard or media settings. I have 148 x 148 set as the thumbnail size.
You can see an example here, where the category image has gone blurry: http://www.reallywildflowers.co.uk/products-page/consultancy-services/
It strange, because the issue doesn't appear immediately. Sometimes its a day later or a week.
Please, why are the images defaulting to a low quality thumbnail size? And how do I stop it doing this?