that happened to me yesterday, too. no issues on my phone/ipad, but my desktop pc with chrome was pulling the download window up. clearing my cache solved it, but it took a couple hours of trying to figure out what was going on before i tried that route. i could manually enter the subforum addresses and navigate within those just fine. but going to the main needlesandgrooves.com page, either through links here or by entering manually through the address bar made the download window pop up.
fyi @RenegadeMonster, this issue arising seemed to coincide with the bluehost issue being resolved on their end.
The issue we had the other day was a corrupted Apache configuration file. So I guess it's possible very strange things could have occurred such as the forum wanting to download itself.
The issue has been resolved, but I suspect the issue now is just peoples caches containing corrupted data. It likely may only effect people who visited the forum while we were having the issues. @AndySlash, I suspect it only effected the home page for you as that was all you were trying to hit when the forum was having issues.
If anyone is having this issue still clearing your cache will resolve it.