Opera 7.21 preview 5 (build 3216) changelog 
(7.21 preview 5 -> 7.21 preview 4): 
-------------------------------------------


Fix for aggressive content guessing when MIME type is unreliable (if setting is chosen in Preferences). ISO files 
and others got extension WBMP and were loaded inline as if they were images. Content guessing is turned off for 
BMP, WBMP, XBM, ICO.