Index: typo3/sysext/t3skin/extjs/xtheme-t3skin.css
===================================================================
--- typo3/sysext/t3skin/extjs/xtheme-t3skin.css	(Revision 10011)
+++ typo3/sysext/t3skin/extjs/xtheme-t3skin.css	(Arbeitskopie)
@@ -503,7 +503,8 @@
 }
 
 /* mask while loading */
-.t3-mask-loading .ext-el-mask {
+.t3-mask-loading .ext-el-mask,
+.x-panel .ext-el-mask {
 	background-color: #f8f8f8;
 }