ikeliu sprendima ateities kartoms:) tik kas gali pasakyti, kaip man kelis  
menesius viskas veike????
tik nebeversiu i LT, pakopinu is mano posto kitame forume:

the problem was determining file extension in this line:
fileUpload1.getUploadedFile().getContentType().substring(7)


because different browsers differently return file name (Some browsers  
return complete path name, some don't) and then I pass bad "format"  
parameter to my getPreview() method. The resolution is from this  
link:http://www.netbeans.org/kb/60/web/fileupload.html determining file  
name, then extension

String uploadedFileName = fileUpload1.getUploadedFile().getOriginalName();
         int index = uploadedFileName.lastIndexOf('/');
         String justFileName;
         if ( index >= 0) {
             justFileName = uploadedFileName.substring( index + 1 );
         } else {
             index = uploadedFileName.lastIndexOf('\\');
             if (index >= 0) {
                 justFileName = uploadedFileName.substring( index + 1 );
             } else {
                 justFileName = uploadedFileName;
             }
         }


extension:

justFileName.substring(justFileName.lastIndexOf(".")+1)