Pictures taken with my 1D Mark IV show a blue horizontal line at the bottom from ISO 400 onwards. So far nobody has been able tot tell me the cause of this problem. The body is still quite new (15000 pics taken).
Your answer certainly is of some use. Thanks for all your trouble and time you put into it. Next step will be to find the right software. I'll begin with pixelfixer.
https://picasaweb.google.com/103470919743498275798/20140201?authkey=Gv1sRgCMCe_LzY2cih_QE#5975415047177679474 I hope this RAW picture will help, so far no solutions offered did work.
