Error MAC Header Length

I have SusE Linux 8.1 with a DSL and a ISDN connection , configured by YAST. This connections works fine. Now, I will use VPN-Client 4.0 from Cisco on this connections.
ISDN make no problems, but with DSL I get in /var/log/messages immediately after the vpn connect command the following error: "kernel: unknown mac header length (22)"

Decreasing from the MTU Value will not solve this problem. I think the pppoe can't handle the longer MAC header with the VPN data.

How can i resolve this problem?

Thank you for your help in advance
Michael Beppler

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* Michael Beppler	   e-mail:Michael.Beppler@hrz.uni-giessen.de	*

* Hochschulrechenzentrum der						*

* Justus-Liebig Universitaet Giessen					*

* Heinrich-Buff-Ring 44							*


* 35392 Giessen, Germany						*


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* phone: 0641-9913032							*


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