Joe Walsh wants everyone to know -- HE PAYS HIS CHILD SUPPORT!!! ... unlike another Joe Walsh.

We got the famous Eagle Monday at LAX and asked about former Illinois GOP Congressman Joe Walsh, who was so behind on child support he had the distinction of being the only U.S. Representative to have his wages garnished.

Joe's taken a ration of crap from people who confused him with the deadbeat dad ... it's pretty clear ... Joe (the musician) is getting pretty damn tired of the confusion.