resuming a download

is it possible for ioftpd to allow someone to resume a download?

if a user disconnects mid transfer and then reconnects the download is not resumed. i dont know if this has been a problem for me before and just not noticed it, but someone keeps disconnecting and downloads dont resume. their client is set to auto resume and even when changing it to "ask" and then manual selecting resume it still starts a 0 byte.

is this only allowed in the registered version or did i just alter a setting somewhere that messed it up, i did a quick search with no luck and tried the kb and didnt see anything that helped...