FileSizeLimitInBytes is set to 5000000 which limits your download so just set it to maximum! (this is client side btw on windows 7)
- Right click on the FileSizeLimitInBytes and click Modify
- Click on Decimal
- In the Value data box, type 4294967295, and then click OK. Note this sets the maximum you can download from the Webdav to 4 gig at one time, I haven’t figured out how to make it unlimited so if you want to download more you need to split it up.