Now that my phone status is rooted with Motocache1's update, I don't have to worry about having to reinstall SPRecovery anymore. When I power+x into SPRecovery, I usually am still unable to mount the sdcard getting the usual E:Can't mount /dev/block/mmcblk0p1 [blahblah] message. When I reboot from SPRecovery, to save time I make sure I use the D-up trick to prevent the phone from booting and instead go into bootloader.(I should have used this trick when I wasn't rooted to avoid repeated SPRecovery reinstalls). From there I can power down and then power+x back up into SPRecovery. Eventually, I am able to mount the sdcard in SPRecovery without getting an error message. One thing seems to help a bit: if I clear the cache in SPRecovery, the next time I come back in it seems my chance of a sdcard mount success is much better; not 100% though. Maybe it helps, or maybe it's just been random correlation.
I should also note: before rooting success and before trying to cycle through multiple reinstalls of SPRecovery, I wiped my scard using SPRecovery and also reformatted it from within the phone's OS. This didn't seem to have any immediate effect on SPRecovery's ability to mount the sdcard, but I provide this in the interest of full information. Unlike others reporting this problem, I've never pulled the battery or sdcard from my phone in this process.