WITH COMMA I'm watching The Incredible Hulk, with Bill Bixby. (Means I'm watching The Incredible Hulk, starring Bill Bixby.) WITHOUT COMMA I'm watching The Incredible Hulk with Bill Bixby. (Means that a guy named Bill Bixby as well as I are watching The Incredible Hulk together.) Am I correct on both counts?
Yes, but many people don't understand commas, so regardless of what's correct you're better off phrasing the sentence so there's no ambiguity. "I'm watching The Incredible Hulk, starring Bill Bixby" is unambiguous. I'd go with that.
The letter I received from you two weeks ago, I Noticed a comma in the middle of a phrase It changed the meaning Did you intend this? One stroke and you've consumed my waking days!