This helped me, maybe it will help others too:



Slow Transfer Rates with ICS and High-Bandwidth Devices



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The information in this article applies to:

Microsoft Windows 98 Second Edition

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IMPORTANT : This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore it if a problem occurs. For information about how to do this, view the "Restoring the Registry" Help topic in Regedit.exe or the "Restoring a Registry Key" Help topic in Regedt32.exe.


SYMPTOMS
If an Internet Connection Sharing (ICS) host is using a high-bandwidth connection to the Internet, the transfer rate may be slower than the medium's typical rate.



RESOLUTION
WARNING : Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

To resolve this issue:

Click Start, click Run, type regedit in the Open box, and then press ENTER.


Locate and click the following registry key:


HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\ICSharing\Settings\General\InternetMTU
Right-click the registry key, and then click Delete.


Restart your computer.


NOTE : You should not remove this registry key if you are using a dial-up connection with a modem over an analog phone line.


Provided by
Microsoft Product Support Services