svcHost.EXE on XP and firewall

I have two systems a Win2000 system and a new XP system.
I have Norton personal firewall and a nat router.

The windows 2000 system works fine.

But the XP computer trys to use svcHost.exe to connect to userserver.agni.lindenlab.com (66.150.244.151)

Is there any reason SL should be trying to use windows networking?

Edited: To add, and added "and prevent's login" to subject

Disabling the firewall or granting svchost.exe full internet access makes it work, but that opens me up to lot's of posible atacks. I'm not parinoid! They are out to get me.

Here is a snip of the SecondLife.log file.
-------------------------------
2006-05-01T23:18:18Z INFO: Initializing messaging system...
2006-05-01T23:18:18Z INFO: Message template checksum = b43055a3
2006-05-01T23:18:18Z INFO: attempting to connect on port 0
2006-05-01T23:18:18Z INFO: connected on port 0
2006-05-01T23:18:18Z INFO: startNet - receive buffer size : 400000
2006-05-01T23:18:18Z INFO: startNet - send buffer size : 400000
2006-05-01T23:18:18Z INFO: Message template version matches prehash version number
2006-05-01T23:18:18Z INFO: LLXferManager ack throttle min rate: 2.66667e+006
2006-05-01T23:18:18Z INFO: LLXferManager ack throttle actual rate: 2.93333e+006
2006-05-01T23:18:18Z INFO: LLXferManager ack throttle min rate: 8000
2006-05-01T23:18:18Z INFO: LLXferManager ack throttle actual rate: 150000
2006-05-01T23:18:18Z INFO: AssetStorage: Setting upstream provider to 0.0.0.0:12036
2006-05-01T23:18:18Z INFO: LLAudioEngine_FMOD::init() initializing FMOD
2006-05-01T23:18:18Z INFO: LLAudioEngine_FMOD::init() FMOD initialized correctly
2006-05-01T23:18:50Z INFO: app_request_quit
2006-05-01T23:18:50Z INFO: Exiting main_loop
2006-05-01T23:18:50Z INFO: Disconnecting viewer!
2006-05-01T23:18:50Z INFO: Viewer disconnected
2006-05-01T23:18:50Z INFO: Cleaning Up

Get a router, you will have NAT protection, a web GUI to configure all the settings you want and wont need a software firewall to slow your computer down and give you more issues.

I have a NAT firewall/router. But I never trust one "thing, device, person, or company".
Everything malfunctions, has holes, or contains something bad.

I can set it to work for now, but I'd like to know WHY SL needs to invoke this.
Or is there something wrong with the computer?

I'll Install SL on anuther XP computer and see if it does it there.

Simply put.
I have to either find the cause or stop using company computers to play SL.
Or just stop playing SL since I can't afford a new PC right now.

Note: I work at home. So it's not like I'm sitting at work playing SL, but the computers have access to both my personal credit card info and company secret stuff.

Edit: it's also anoying since it keeps changing where it's trying to connect to.
It now wants to connect to 72.5.12.19 Edit: That translates to sim869.agni.lindenlab.com