Using (extended) HTML export can results in an html based mlp file

I save my playlist the first time as a HTML, in order to create a (Word) file to add some relevant information about track and other stuff. When I add more tracks and items to the playlist and save it as mlp file it sometimes occurs, that the mlp containts the html data, making it unsuitable for broadcasting. (When i rename the file to HMTL I can see the regular HTML output)

I am not able to reproduce it at the moment. But it happend with me before in Mairlist 6 but also in Mairlist 7. I am affraid to use this function, because I lose hours of work. I can rebuild it, but it is a big suprise, when you want to start your broadcast and everything is gone.

Does anyone have any thoughts about this issue?