for 1.1.4, it is advisable to do a firmware restore, not only using update. and after that u can use ZiPhone. or u can try using iPlus (like ZiPhone, but also installs BSD subsystem)
and yes, better to do Restore than doing Update, coz if u select update it will still keep the jailbreak files, apps, etc etc on the iPhone. and most of the apps can't already be used on 1.1.4. plus heard that it will be of some conflict with other version of jailbreaks (dev, Nate's).
about bricking the iPhone, no worry anymore! the step is super easy. plus in fact ZiPhone and iPlus revived some dead iPhones before (that showed "Repair Needed"). only one button and it will perform Activation, Jailbreak and Unlock. and all of that is only under 4 minutes!

u need to select Do It All la.

haha...i know that u have read an older guide on using ZiPhone with 1.1.3 and 1.1.4. at that time the patch is not included yet in the package, so we used to need to do it manually. but now, just select Do It All button (it is only one button on the top)

hehe thanks man... the phone is working already