Please help re upload issues!

I attempted to upload some pictures to my website, (I use FatCow to host and the included Weebly upload software) Safari denies access to my files and gives no explanation as to why! After consulting with the FatCow support line, they suggested using FireFox to see if that work and lo, it did and all well! FatCow support suggested that there may a problem with Safari. I have not knowingly changed any settings and all previous uploads have been successful using Safari! Any thoughts?