Ah - that's because Internet Explorer thinks it's supposed to just open the replays with that specific version of Toribash.
You need to remove the association for .RPL
Open 'my computer' (any other folder will do TBH)
Click the 'tools' menu, then 'folder options'
Click the 'file types' tab
Then just find .RPL in the list & delete it.
To re-associate it with the newer version of TB try & open a replay & when it asks what with point it towards the newer version.
Since 3.7 is due out (supposedly tomorrow) I'd save doing this until it's released.