Safari opens only these forums and other Apple pages?

Question

I had to remove the router from my iMac last night, so I set the Network panel to work with the DSL modem only. After doing so, Safari only connets and opens the Apple forums and other Apple pages, nothing else. Also, Sotware Update won't work.
I have reinstalled the router, and right now the Network panel indicates that the network is working, and that the computer is connected to the Internet via the router and modem. It does not matter how many times I "Create A new Location" and then apply it. Safari won't work with any of the bookmarks, except for the Apple bookmarks.
I restarted the computer from the (backup) external hard drive and ran Safari from there, and it works fine. However, I followed the advise of an Apple Technician on a chat, and was told that I could drag Safari from the external HD to the internal, and replace Safari with it. I did so, and then restarted from the internal HD, placed the Safari alias in the trash, created a new alias and put it in the Dock, and used Safari. But Safari is having the same problems.
It seems that both Safari, and Software Update follow the same path from the computer to the Internet, so i am trying to figure with files in the System have screwed-up.
Do you have any ideas of what the problem with Safari may be?

Answer 1

I will respond to myself to keep you informed of the progress with my problems and Safari/Software Update:
1. I created another account, but again there was no change with Safari nor with Software Update. I am certain that the problem is related to Software, perhaps Preferences and such.
2. However, since I don't know enough about OS X to mess around with it, I decided to start from the LaCie external HD as I did before, and proceeded to perform a "Smart Update" with SuperDuper. Before the Smart Update, I printed the last unread e-mail in the mailboxes, since I know that SuperDuper would erase those. I backed the iMac's HD a couple of days ago, before encountering all of these problems with Safari, so all the files and applications are fresh and in good order.
3. I am replaying to myself using Safari, after I restarted from the iMac's internal HD. Safari now works as well as ever, and I am certain that Sotfware Update will work fine, too.
I hope that Apple takes notes on the problems several of us are having with Safari. Just for the records: This version of Safari is the latest in Mac OS 10.4.2. A week or so ago, I upgraded OS 10.3.9 to OS 10.4, and had quite a lot of trouble with the Network panel. Regardless of the settings to use a router and modem, or jut the DSL modem, a connection to the server could not be established, and whenever such connection was possible, Safari would only open the Apple pages, and Software Update would not work.
I ended-up erasing the hard drive and reinstalling Mac OS 10.4 three more times, for a total of four, before I could get Safari and Software Update to work. On the last attempt, the only difference from the other attempts was that this time I didn't dare use Safari until every little update was installed by Software Update. Now, please note that the problems I had then were not exactly the same, since this time Network Diagnostics passed the connection test with flying colors. The previous times, a connection could not be established 99% of the time. But even though the problems were not exactly the same, I believe that whatever happens, to Safari, FireFox (FireFox was not working), and Software Update is related to whatever path these applications follow toward an Internet connection.