Norton screws up my internet access.

I have been using Norton for years now with very little trouble until now. I recently upgraded my dinosaur pc with an Asus M4N68T-M (AM3) motherboard and reinstalled it, as i had around 300 days of subscription left. This has caused a hell of a lot of problems with my internet connection. From the moment i installed it, i was getting Content Encoding Errors on websites, pages not loading fully, scrambled pictures, etc. I thought it may be my ISP but that side of things is fine. I thought it may be the Nvidia Nforce chipset of the board, so i bought a pci ethernet card. It made no difference. I noticed then that if i left Norton uninstalled, the faults never happened. I reinstalled, the problem came back, uninstalled again and it vanished again. Is this a common problem? And if so, is there a workaround? I really like Norton but ifthis is a thing i'll have to put up with, i'll need to use another antivirus.

 

Here's a spec of my machine.

 

Operating System
            MS Windows 7 Home Premium 64-bit
        CPU
            AMD Athlon II X4 635    22 °C
            Propus 45nm Technology
        RAM
            2.0GB Single-Channel DDR3 @ 669MHz (9-9-9-24)
        Motherboard
            ASUSTeK Computer INC. M4N68T-M (AM3)
        Graphics
            SDM-S95AR/ER @ 1280x1024
            256MB GeForce 7025 / nForce 630a (ASUStek Computer Inc)
        Hard Drives
            977GB Hitachi Hitachi HDS721010CLA SCSI Disk Device (SCSI)
            977GB Western Digital WDC WD10 EACS-00ZJB0 SCSI Disk Device (SCSI)
        Optical Drives
            PIONEER DVD-RW  DVR-107D ATA Device
            PIONEER DVD-RW  DVR-118L ATA Device
        Audio
            SB Audigy
Operating System
    MS Windows 7 Home Premium 64-bit