I found an issue with my Yii asset manager setup and yii-bootstrap. See https://github.com/yiisoft/yii/issues/1853 for details.
Short version: In Bootstrap.php (line 328);
Yii::app()->assetManager->publish($assetsPath, false, -1, YII_DEBUG)
If YII_DEBUG is true, forceCopy conflicts with linkAssets.
I'd propose to remove that setting and just configure it via config/main.php
Tested with 1.1.13-RC and Yii-Bootstrap 1.2.0