I followed the instructions in post 22 and 23 and it fixed my boot animations. This is exactly what I did:

1) download the French v20A (hxxp://csmg.lgmobile.com:9002/swdata/WEBSW/GT540/ANEUBK/V20a_00/V20A_00.kdz) and the out.kdz (hxxp://narod.ru/disk/25473801000/out.kdz.html)
2) Take out your battery, SIM and SD card
3) plug USB into PC (but not phone yet)
4) hold Vol - button and plug USB into phone - phone goes into Download Mode
5) run KDZ Updater, put it into CS_Emergency mode
6) select French V20A rom and flash it
7) when it's finished pull out USB again and hold Vol - and reinsert USB to put phone back in Download Mode
8) in KDZ Updater (still in CS_Emergency mode) select out.kdz and flash it

You should now have your boot anims back and you can flash whatever rom you want to use.