Keep getting invalid destination port message every 30 sec in Console

Question

Hi, this is my first post so be easy on me. I have been checking up on a possible attack on my website and looking for things that may have caused visits/dowloads to blow out. 
While do this I looked at my Console app on my iMac 2.4 Ghz Intel Core 2 Duo running 10.6.8 and notice that every 30 seconds there is a dual message:
6/09/11 4:39:38 PM imagent[161] Unable to create APS daemon connection: (ipc/send) invalid destination port
6/08/11 4;39:38 PM imagent[161] Unable to set enabled topics: (ipc/send) invalid destination port
This action then repeats itself every 30 seconds non stop. Every now and then the odd "normal" error will appear with various apps but this is constant.
The bottom of the Console window reads 4001 messages from 5/09/11 12:30:21 tp 6/09/11 4:57:08 PM
I have looked on the web to try and find out what the 161 refers to and what meaning of the phrases are, but none address 161 specifically and most seem to be in foreign languages.
Your help will be greatly appreciated
Matt

Answer 1

Thanks for that. I had a look at Facetime and had vitually forgottten about it having never used it. I tired about 8 months ago and coould never log in. All I ever got was the spinning wheel at log in, which is exactly what I have just got know as I tried to open it again.
I am wondering if it has been going throogh this process ever since.
Anyway I looked into the ~/Library/LaunchAgents and the nearest I can find are com.apple.apsd-ft.plist, com.apple.FTMonitor.plist, which may relate to Facetime and then there is com.apple.imagent.plist
which is the one that seems to be causing the problem.
Now when I read your reply and did the search using your parameters and the very first reply said that:
"As you probably know, you can get FaceTime invitations even if you have quit FaceTime. That feature is provided by "imagent".
Unless you have configured the FaceTime > Preferences... > FaceTimesetting to "OFF", you are still using "imagent" (and a couple of other support processes) even if you have "Quit" Facetime.
Once you set the preference to "OFF", imagent will go away, but you will not be able to receive any incoming FaceTime invitations until it is turned ON again."
Well as I can't log into Facetime I can't get to Preferences, to turn it off.  Now bear in mind I am new to this type of thing, but I have heard some people say that you can throw plist's in the trash and that the application regenerates a new problem free version.
Is this what you suggest I do and if so which of the above three would be the one(s) to delete?
And thank you very much for the very quick reply, much appreciated
Matt