I don't know off hand, however some anti-spyware may or will detect the restricted changing of the homepage as a hijack, not that some malware couldn't change it anyways even if locked.
Have had both for years, never a conflict. Also use Spywareguard. I just changed my home page, and both Spywareguard and SAS caught the change and required confirmation. No warning from Spywareblaster, not sure why.
Spywareguard is not passive, and is said to conflict with Spybot's TeaTimer. I think it runs a bit heavy, and other members here maintain that it is obsolete.