well unless you give a link to a webpage to see this, one can only guess. Two obvious things that spring to mind.
Firstly you are using a compliant imaage that can be read by browsers, such as a Jpeg or GIF format? If yo u upload a specific file for your own camera or imaging software then a browser will not be able to interpret it, thus getting a corupt look.
Secondly in which mode did you upload your images? There are two modes in which your files can be uploaded, ASCII or Binary. All graphics files should be uploaded in Binary format. uploading in ASCII can cause corruption. Consult your File transfer interface or software.
Well apart from having mroe infomation as to what format your images are in and actully see an example thers not much else i can think off at this stage. Hope this helps.