Why are  getting inserted into the beginning of the file??

 After our build we do some unit testing. I take the output of MStests which is a trx file and convert it to htm. This way people can download the file and use it for reports. However RTC seems to think it need to edit the file when I upload this to a build result. Why does RTC insert these characters ï»¿? It corrupts the file so it won't load properly in IE or it will display those characters at the top of the page. I checked the source file and of course its not there so its RTC modifying the file as its attached. RTC should not be touching the file at all! All it needs to do is attach it to the build result. I've dealt with RTC doing this to source code so much that the file became corrupted and wouldn't compile anymore until we removed all the ï»¿ at the beginning of the file.