There're basically two questions in your post. Let's answer them one by one.
Last night I ran an offline scan and detected this virus in C:\Program Files\Sygate\SPF\rawlog.log.
If it was SQLSlammer, it's not such a deal. I mean, I can imagine such a situation very well. The Sygate RawLog file (given its name) probably stores individual packets coming to your machine, on certain ports. So it's quite possible that a remote machine send you a packet with SQLSlammer payload, and avast is now picking it up in the log... There's nothing to worry about here, really...
It w
ould appear WebShield and Sygate are incompatible as expessed in several recent threads.
I think you misunderstood the problem. It's the fact that Sygate has problems with local proxies, in the sense that it's not able to control traffic going thru them. However, in build 4.6.623, WebShield was modified in the sense that it's now opt-in only. I.e. it filters traffic coming from certain processes only, thus mitigating the problem to a large extent.
For more, please a number of Sygate-WebShield related threads on this forum.
Thanks
Vlk