noob needs help

[craftyone714]

Hello i am a noob when it comes to flashing my PPC-6700 sprint phone. its the first time for me. I am trying to flash the latest BIG j flash and have unlocked the extended rom and cleared the sprint stuff off of it. put phone in bootloader mode and ran the upgrade utility. the upgrade utility is where i get the trouble. it will come up with a screen. "checking the information on your device... please wait..." this screen does not go away and eventually i will see a screen showing the upgrade to and from versions... but they are all blank. clicking next says sucessful and to reset the device with soft keys. but it has no effect. Also the program will do the same thing with no cable even hooked to the phone.
Please point me in the right direction