Jessica Simpson insisted she was too ill to visit children in Kenya, where she has planned a 10-day charity trip.
The NEWLYWEDS star is said to have spent just two days with Operation Smile - a charity repairing facial deformities of children.
She has interrupted her charity visit and embarked on a recreational trip in the Masai Mara National Reserve last week.
"Jessica got sick, like people do, and couldn't get out of bed", a representative for the charity said.
According to a hotel insider, "Simpson was not ill; no doctor was called out to see her".
Operation Smile spokesperson admitted that the safari, which is thought to have cost a staggering $12,500, "was scheduled downtime".
Meanwhile, Jessica Simpson is rumored to have faced some marriage problems.
Speaking about her husband Nick, Simpson said: "hopefully mine and Nick's story will continue for the rest of our lives, like what we vowed, through sickness and in health."
The two got married in October 26, 2002 and, during the summer of 2003, both starred in the reality show Newlyweds.
During the past twelve months, there were rumors about Nick Lachey's infidelity with a college student, Danielle Calo, or with the girlfriend of Lachey's best pal Chad Leslie.
It has also been written that Jessica is the one to blame for the couple's breaking up, because of her "wild partying and frequent bed guests."
Speculations were prompted again when Jessica spend the third marriage anniversary without her husband.
So, the chain kept stretching, until the singer said 'no more'.
Jessica Simpson is currently working on her fourth album, "And the Band Plays On".