LOS ANGELES (thefutoncritic.com) -- CBS is giving its Monday lineup a makeover as "The Class" and "How I Met Your Mother" are set to trade time slots beginning next week.

The news, expected to be announced tomorrow, comes just three weeks into the Eye's 2006-07 season.

"The Class" posted a preliminary 2.8 adults 18-49 rating last night, barely beating out ABC's "Wife Swap" (2.7) for third place in the 8:00/7:00c half-hour, while its overall numbers in the key demographic have fallen 24.32% since its premiere.

Conversely "Mother" posted a 20% growth from "The Class's" 18-49 audience last night and has only lost 5.26% of said viewership since its second season launch on September 18.

Interestingly enough, CBS had originally slated "Mother" to lead off its Monday lineup before opting to go with "The Class" back in July.

Meanwhile in related news, the Eye is also understood to be moving forward with a full season of 22 episodes for "The New Adventures of Old Christine." The sophomore comedy posted a season high 4.5 adults 18-49 rating last night while its 83.54% average retention rate of lead-in "Two and a Half Men" is up from last year's "Men" lead-out "Out of Practice" (80.96%) during the same period.