Zensation 2014: 1.6.0.6 The barred price on promotion that does not appear

Zensation 2014: prestashop 1.6.0.6
Hello, when you launch a promotion, the barred price on promotion does not appear in the material master. When you reload the page, it appears during loading and then disappears.
Do you have any idea of the problem?
Cordially.