No longer able to open the MHT log files in IE

This change has recently occurred and I've searched the web in order to try and solve it with no luck. 



All of a sudden I am no longer able to open the TC MHT log files in IE. 

I download the file from our build sever and double click on it.

What used to happen is it would open with no problems in IE. 



Now, after double clicking, it opens the view downloads dialog window and asks me to save the file. 

I do this, it saves and the button changes to open.

So I click on Open but.... another instance of the file appears in the view download window and it asks me to save the file again. 



I tried changing the security setting to low in IE but this didn't work. 

I also tried reassigning IE as the default program to open the file type with. 



I'm using IE10 and windows 7. 



Any suggestions would be great thanks!