Hi – I am having a similar issue with my site. Instead of the home page coming up… I get a download.gz file. Found that re-publishing a sticky post that I had on the homepage fixed the issue temporarily. But it seems to be recurring. Any suggestions or thoughts on what it might be.
I have disables Super Cache as well as a XML site generator plugin which I though may have been causing this. But it does not appear to have fixed the issue permanently.