lion upgrade fails with general error

New to mac troubleshooting but not new to mac.
Yes i have followed all pre upgrade steps both here and other sites.
Everything was going fine and the MBP rebooted and continued till it gets to the 19 min remaining point and then i get the error,
"The installer encountered an error that caused the installation to fail. Contact the software manufacturer for assistance."
Now i'm stuck in a loop. Not sure what to try now.

Is it time to start a clean install?

So I guess can anyone tell me the keyboard key(s) to press to do a clean install and boot from the SL install disk? I had hoped someone would know this error.

Do you have your original Snow Leopard install media? If you do, insert the Snow Leopard DVD, reboot and hold down the OPTION or C key as soon as you hear the chime. Once it boots to the Snow Leopard installer, go to the top menu "Utilities", "Disk Utility". Highlight your drive on the left side and then select erase. Choose Mac OS Journaled, name the drive, and press erase again.

After it erases the drive and formats it, you can continue to install Snow Leopard. Note that this procedure destroys all your data! So be sure to backup everything first before doing it.

When i do this, i hear the dvd spin up 4 times and then the dvd ejects and i see

1) with the option key, i see to drive icons. One says mac os x installer and one recovery hd.
2) with the c key, the lion install kicks in.

Thanks for the reply and i hope you can continue to send ideas

What kind of Snow Leopard disk are you trying to boot from? It sounds like your system is just ignoring the SL disk and going right to the hard drive with the incomplete install of Lion.

Are you sure you have the correct SL disk for your machine? Or your SL disk could be scratched or marked.

The dvd says macbook pro mac os x install disc 1. It and disc 2 are the ones that came with the MBP.

I was able to see my time machine drive but it told me there was an issue with the drive and i could not repair/restore with it ( OK, didnt test time machine first )

Thanks again for the reply. Looks like my data may be gone, just want to have the mac working. I hope the upgrade was going to be fine but things happen.