SP1 is a pre-release version of software. Microsoft make one or two release candidates RC1, RC2, etc available to customers in advance of the official release. A release candidate is like a "sneak preview" of the final release with the goal of ironing out any serious bugs may yet surface in the "wild" before the general public uses it to give them time to be fixed.
There can be hundreds of reasons why and they cant be addressed because of the Release Candidate nature of the product, If they are affecting the use of your computer just uninstall it as its for testing purposes only, for example AVG would install SP1 to identify any fix
any clichés or bugs before the final release.