Just wanted to add another post to say that this bug is still happening under OS 10.9.4, but none of the suggestions worked for me until I tried the Terminal solution from snsh (and maybe from others earlier).
In OS's earlier than Mavericks I always just used Activity Monitor to force them both to quit and this worked every time. Today it didn't, as others have described, because they both relaunched so quickly. Going offline made no difference.
Those of you who don't like the sound of using Terminal, its very easy, just follow what snsh says, it worked perfectly. As soon as the installer had finished I quit Terminal and noticed that both synservicesagent and the Microsoft Database Daemon both launched immediately (could see them reappear in the Activity Monitor window).
Another astonishing example of poor coding by Microsoft.
Thanks snsh