Poor Thumbnail Settings

[smmna]

For some reason, no matter how much I try to change the thumbnail settings in the configuration, the thumbnails always have a poor quality. I tried uploading the same picture in a different gallery in a different website, and the result is below (the first is the one uploaded to the different gallery). They have the same configuration settings, other than the thumbnail size. But, even when they used to have the same size, the thumbnail's quality was still poor. Is this because I was unable to upload something or because of the host? They're both hosted by different sites. I installed both manually, if that helps.

[Αndré]

no matter how much I try to change the thumbnail settings in the configuration, the thumbnails always have a poor quality

Do you uploaded the picture again after you changed the settings? Please post links and test user accounts for both of your galleries.