electrical outlet replacement

I've replaced 8 outlets in one room, which are on 2 separate circuits. But now both circuit breakers trip when I turn tem on. Also ALL the outlts work when either one OR the other breker is on and the othe off. Does this make any sense! What am I not seeing here????? I didn't have any Problems in the other rooms.
Note: some outlets have 2 white and 2 black wires, and a few of them have 4 wires: whit, black and red, if this makes any difference. I'm at the point of calling in the "professionals".

 

There is a very good chance somewhere along the line you connected the two circuits together. One possibilty is one of the old receptacles was what they called a split receptacle which means power from one circuit was one half and power from another circuit was on the other half. Check your old receptacles and see if one of them had the side tab on the brass side cut.
go back to the receptacles with the black red and white and disconnect the wires test these wires afterwards to see if you have power on both the red and the black turn off one breaker and test again if power stops with one breaker off then that is your second circuit you can either split the receptacle as it might of been before or disconnect one of the two hots and marrette it off.
Let me know if this helped

 

The ones with the black and the red were either a multiwire or switched recepticle. You probably need to break the tab on these.

 

gard, your suggestion was correct!! KUDOS to you.
It took some time to trace it out, as I wasn't sure which outlet came from where. And, I never thought to look at the tabs. The next room on the agenda, I will be sure to look at the tabs AND number each outlet (old & new) as to their location.
THANKS AGAIN!! MERRY CHRISTMAS!!