Modern anti-virus and security packages work by integrating with the operating system at a very low level, so that they can intercept malicious activities from any potential threat.
An inherent problem with this approach is that it affects the performance of the system. How much or how little depends on the specific anti virus program in question, and may vary from version to version.
Also, some packages may restrict the actions of an application (such as HSMWorks), and prevent correct installation or operation.
So before reporting an installation or performance problem, please try to disable your security package and see if the problem disappears. In some cases disabling the package may not be enough, and uninstalling the package will be necessary.