Here, this is some of my lessons and experience.
My LG OPT V factory version is 2.2.2. And these steps are what I did,
1, root with Gingerbread, all right;
2, download the ROM manger from market, and flash the 3.2.0.1 clockworkmod recovery, all right;
3, boot to the recovery mode, the LG logo displayed and then gone, but no any others things displayed, it kept a black screen;
4, take out the battery, and put in it, then press home + vol down + power, the LG logo displayed and gone, and still the display the black screen. This will not change no matter how long you wait;
5, take out battery to reboot, all right, the factory ROM still works;
6, flash the recovery with the ROMtools 2.31, step by step just like the instruction, finally, failed, because it try to run the psneuter, and failed, so the flashing cant to be continued;
7, with the terminal emulator and flash_image, flash the asopCWMod recovery, still can not boot to the recovery mode;
8, flash the Xionia_CWMA, boot to recovery, works;
9, backup the factory rom, you will know this almost save my phone later;
10, wipe data, wipe cache, ..., flash BACKCM 08312011, it display the signature is not correct when verifying;
11, check the md5, it is the same as the website, toggle the verify signature setting, flash it,, OK, reboot, after the LG logo displayed and gone, nothing displayed, even though I can hear DANG DANG when press the vol up button;
12, reboot to recovery, and flash the CM 08202011, signature verifying is all right, reboot, still nothing displayed;
13, flash the 80102011 CM, the same;
14, flash the MIUI rom, the same;
15, flash the backup factory ROM, reboot, works.
These are what I did, it took a really long time to do research your post and find ways, but finally, I still can not use a custom ROM only because this is LG OPT V 2.2.2, I used do this to a LG OPT V 2.2.1, and it was so easy and successful.
BTW, the HOTSPOT of quick settings does not works on this 2.2.2, and it works well on 2.2.1, this is why I try so many times to flash a new ROM.
Do any of you have such experience or have any idea of this?
THANKS.

 

Yes, I used the Gingerbreak.ap, and also I installed the busybox from the market.

The flash_image I used is for another post, not from the ginger or busybox, and this is why it works.

Quick settings works on 2.2.2, but when toggle the "Hot Spot", I found that it will open the 3G and close the wifi, this is correct. But then the 3G will be closed imminently, I think this might be because of the service of LG, it close the 3G when trying to use as a hot spot.

As I did, the button of the CWM and the Xionia recovery is the same, I mean both are the camera button, I tried the home and nemu, they are no use then.

 

The recovery is Xionia_CWMA_12518.4_VM_Recovery.zip.

Thanks.