Hi
I have an o2 german Pre, so with 1.1.3 firmware. I have flashed it with the 1.2.1 Bell firmware (I want to keep the french language
) and here is the process to not loose the app catalog (should be the same withe sprint firmware).
Open the webosdoctor jar of your "normal" firmware with something like 7zip (don't extract de jar, just open it). Click on "resources". You will see 2 .tar files. In my case, with the german 1.1.3 O2 firmware, i have "wr.tar" and "webos.tar".
Click on "wr.tar" and you will find 3 .ipk files. Extract those .ipk directly on your Pre (so connect you pre to your PC and choose USB drive
)
Go back and click on "webos.tar", then click on ".", then click on "nova-cust-image-castle.rootfs.tar.gz", then Click on "nova-cust-image-castle.rootfs.tar", then click on ".", then click on "usr", then click on "palm"a and click on "applications". Extract "com.palm.app.findapps" folder directly to you Pre.
On your Pre, with the terminal app (or from your PC with the SDK), do this :
mount / -oremount,rw
cd /media/internal
/usr/bin/ipkg -o /var install ./your_first_ipk
/usr/bin/ipkg -o /var install ./your_2nd_ipk
/usr/bin/ipkg -o /var install ./your_3rd_ipk
cp -Rf com.palm.app.findapps /usr/palm/applications/
reboot