This is because some older drives freaked out when newer DVD media came out. The new firmware helps the drive cope with these discs -- something similar happened when 4X DVD-R media came out (or was it 8X, I am thinking of the Pioneer A03 problems), older drives could actually be damaged trying to use them (Although I never heard a story of anyone really hurting their drive!) I don't know if the LGs were specifically affected but they could have been. I can't quickly find firmware for the "GCA-4040", I think from the GCA designation it is quite probably a drive that was pre-installed in a PC you bought (From Dell, HP, etc). You should check with the manufacturer for information. ["GSA-4040" would be the full, retail, store-bought drive, and firmware is available, but I don't think it would work on a GCA model)
The only firmware I could find-- and be careful if you choose to use it (i.e., it could cause the drive to malfunction), especially if you don't own a Dell-- is at:
http://support.dell.com/support/downloa ... eid=117870
That said, it kind of sounds like you've been using the discs with no problem (DVDs, not CDs). Firmware upgrades *can* cause more problems than they fix. If you're using the discs, you should be ok. A firmware upgrade may help your drive write CDs better, but it may make things worse. That model drive is quite old, I really don't remember much about LG's reputation back then.