Hi,
LifeRay IDE 1.3.1 depends on Sapphire 0.3.0, while Blue/Bling 9.1 use Sapphire 0.2. Since both versions of Sapphire cannot co-exist in the same configuration, the installation of this version of LifeRay will fail.
Blue and Bling 10.0 will use Sapphire 0.3.0, so this conflict will not exist with those versions when released (due in under a month). Until then, you may want to try earlier versions of Liferay IDE which use Sapphire 0.2.0 – perhaps one prior to 1.3.0 which add support for Eclipse 3.7, Bling 9.1 is based on Eclipse 3.6.