dvd not readable

Neither commercially burned movie DVD's or DVD+r's that I have burned on my iMac are readable by the internal SuperDrive or external LaCie DVD burner/player.

Upon insertion, DVD drive spins up and message box: "The disk you inserted was not readable by this computer. Ignore-Eject" This occurs with either the internal or external drive.

In Disk Utility, the inserted DVD (when Verify Disk button is clicked) error message reads: "Invalid BS_impBoot in boot block : 66671c Error: This disk needs to be repaired". A variation of "Invalid BS_impBoot block: xxxxxc" appears with any DVD that is inserted. DVD icon never appears on the Desktop.

All DVD's not readable by my iMac, work normally in a commercial (Panasonic) DVD player.

I had no problem reading or playing any of my DVD's previously on my iMac. It had been about 5-6 months since I had tried and was successful playing a DVD on my iMac's internal drive or external burner/player.

I have already repaired Permissions, reset my PRAM, and unplugged the power cord for 30 seconds after a normal shut-down. No difference.

Here's my system info:

Seems this is a common complaint. Not seen any fixes posted other than: …clean your drive lens.

Anyone have a clue or fix?

thanks in advance,

C.

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