Enroute Bug

I may have asked this question before, but every version of Enroute I have used (3-5.1) has had a bug that costs me a lot of time. 
If I accidentally double click on an Enroute file in Windows File manager,  Windows opens a new Enroute window try to open the file, and in the process of this new Enroute window opening any existing Enroute window already opened then patchily crashes, requiring me to close them all and start over.   Besides the work arround of turning off Enroute file association so that Enroute files can no longer be opened from outside of Enroute.  Is there a way to actually fix this problem?

For me, it just opens enroute in another window. Both work, neither crashes but it does something weird with saving, i forget what though.
(Much nicer than having to restart the computer everytime there's a floating point error or divide by zero error like with my old version I use at home.

If you have Enroute 5 I would make sure you are on the latest version 5.1.0.70, but if you have Enroute 6 then we have an update that should fix an issue when you open a file it only opens Enroute but not the file.