You must be on an EVDO network for you to also recieve calls. Data goes into "dormant" mode and the call comes through, thus file transfers are put on hold.
http://www.pdaphonehome.com/forums/f...play.php?f=169
is a great place to go for all the tweaks you need for your i730. In order to disconnect data and initate a call, you will need SuperDave's Dialparser hack which is available in a thread that I linked above.