IFMX 4.x -> 7.x (SCO)

Hi all, First off, thanks to everyone who has given me assitance in the past. You know who you are and the help was appreciated. Next, my boss has asked me to find out as much info as possible concerning a new conversion that he must do. I will have to be vague about system specs since I have yet to see them. What I DO know is that the system is SCO Unix and the current Informix is 4.? The company wants to move to 7.? Basically, and you can be as vague as I have been :-}, what trap should we look out for? Thanks much, Michael Hoffman