Problem: ComboBox for Reference attribute with CQL Filter keep growing after every edit and finally would grow bigger than the screen width and cause the horizontal scrollbar to appear.
Solution: To edit ./javascripts/cmdbuild/view/common/field/CMBaseCombo.js file
add the following lines
Line 10 add: cmGreatestItemChanged: false,
Line 81 add: this.cmGreatestItemChanged = true;
Line 92 change: if (this.cmGreatestItem && this.cmGreatestItemChanged && this.bodyEl) {
Line 109 add: this.cmGreatestItemChanged = false;
If you apply the edit correctly your reference field attributes would stop growing.