Image not uploading

I am trying to use the "Get device image" feature of WDM but it is failing to communicate with the server. Everything else in WDM is working, the task manager, reboot, shutdown, remote shadow, etc is all working. I don't know what I have set up wrong. Here is what I do:

1) Verify that the the thin client is on and responding to WDM
2) In WDM right click the client and choose "Get device image"
3) The thin client now PXE boots into merlin, this is where it starts to get funny
4) Merlin resolves to our WDM server and tries to connect, on port 80, strange because Merlin is set to ftp (port 23, default). The imaging fails throwing and error 400 (bad request.) and exits.
5) from there it just shutdown and reboots (pxe again, infinite loop)

Like I said, everything else works, which makes me think that this is not an error with either the FTP or webdav servers. Just to be safe though, I gave everyone read/write access to the webdav and FTP root dir. I think the error is in the dhcp scoping option, but I don't know where. I have followed all of the documentation, setting options 192, 190, and 186 to 0x50 (80), 0x1bb (443) and 192.168.112.2 (server ip).

Like I said, I don't know where this is mis-configured, and I am open to all suggestions. Once we get this working deployment will be a breeze. Thank you for all your help!