Denise Richards and Richie Sambora, once one of rock’s hottest couples, apparently discovered that love on the rebound often reopens too many old wounds.

Richards, 41, and Sambora, 52, called it quits after the two argued before the CMT Music Awards last week. Richards signaled the split when she walked the red carpet alone.

“It’s over. They had an epic argument in Nashville and Denise told Richie she couldn’t continue the relationship any longer,” a source to Celebuzz.

Sambora was supposed to be a presenter, but was a no show. At first, he said he had to attend to a personal problem involving his 14-year-old daughter in Los Angeles and later said he was too ill to attend, according to the Web site.

One of the issues that drove the couple apart was Richards’ sudden closeness with ex-husband Charlie Sheen. They have two daughters together, Sam J. Sheen, 8 and Lola Rose Sheen, who turns seven this month.

Sambora, a guitarist for Bon Jovi, and Richards met when both were on the rebound. He’d just left actress Heather Locklear and she had separated from Sheen. She filed divorce papers in 2006, after a stormy attempt at reconciliation.