the only reason you needed yuki's rom was to unlock your sd card...what cab are you trying to install?
you install yuki rom, install the storagelock.cab, unlock your sd card, then turn off the phone. then you flash tiger's rom using flash procedures. what is the issue?
if your phone is freezing, i have said many times before in my posts to your questions, after you flash yuki's v2.1 DO NOT reset nor reboot!!!! just install the storagelock.cab...unlock your sd card using the storage lock app, and turn off the phone.
if you do not know how to send cabs to your phone...i have links in my signature for tutorials!!!! PLEASE READ TUTORIALS AND FOLLOW PROCEDURES
i learned by reading! go to yuki rom's thread and thoroughly read how to do things...read how to install wp7 tutorials thoroughly. i'm not telling you anything new that isn't already documented in the tutorials.
read this too... http://forum.xda-developers.com/show....php?t=1250869