Spaces in file names?

We're experiencing file issues on our site where users click on a hyperlinked file and instead of the pdf opening, they are routed back to our homepage. In some instances, it seems to be related to spaces in file names. Has there been a recent change where spaces in file names would cause users to be re-directed once clicked on? We've never run into this issue before. The only unifying factor is that this seems to be happening specifically to users who are off our network (not VPN'd in) at the time they click on the link.