According to "Us Weekly", TAYLOR SWIFT and CARRIE UNDERWOOD "hate each other" . . . and ordered Grammy execs to keep them separated at Sunday's show.  Another source said, quote, "Taylor feels Carrie is always rude to her, so she steers clear of her."However, Gossip.com found a friend of Taylor's who claims it's "100 percent untrue."  Also . . . Taylor just found out last week that she's the opening act.

MINDY MCCREADY admitted to the Department of Human Family Services that she's been drinking again . . . so they placed her two sons into foster care.  And an Arkansas judge ordered her to be committed to a treatment facility to deal with "mental health and alcohol issues".

Country will be well represented at Sunday's Grammy Awards -- with superstar performers and presenters.

• Taylor Swift will open the show. She's hinted that she'll perform her Song of the Year-nominated "We Will Never Ever Get Back Together."  
• Zac Brown will participate in a tribute to the late Levon Helm.
• Dierks Bentley and Miranda Lambert,who are currently on a joint tour, will perform together on the show.
• Carrie Underwood will sing for the sixth time on the Grammys telecast.
• Three-time nominee Hunter Hayes is also slated to perform.
• Tim McGraw, Faith Hill and Keith Urban will be presenters.

Watch out Miranda -- Blake's got a crush on another woman!  She is a little older!   Check out a clip from Betty White's birthday special with Blake singing to Betty here!