[ffcmike]

A tiledef file isn't something that has to be downloaded (while it is possible to do it that way) but is generated by script, the fact it wouldn't be appearing would suggest a lack of any addtiledef functions, and if the tiledefs don't exist that would suggest why the tileset images wouldn't be downloading as they wouldn't be requested until first used.
Still you could try forcing them to download via a GUPD.