George Lopez' TBS TV show has been cancelled, but there's an even bigger story here -- that Conan O'Brien is failing at the network.

TBS just announced the last show will air tomorrow night. It's been on the air for 2 seasons.

Now the bigger story. It looks like Conan did to George what Jay Leno did to Conan. You'll recall, when Jay Leno came back to NBC, his 10 PM show tanked and killed Conan's ratings.

Well Lopez had the 11 PM time slot for its first season, but then when Conan came to TBS a year ago he took over the 11 PM slot and Lopez moved to midnight -- meaning George was relying on Conan to deliver a good lead-in.

But when the change was made, George's audience plummeted 40%.

On Monday, Conan pulled in an anemic 0.5 rating in the key demographic (18 - 49) with 715,000 viewers -- and that's a pretty typical day. George's ratings hovered around 0.2, with 400,000 viewers.