"connection refused" error with dsl-connection

["Harald Stangl" <harald.stangl@gmx.de>]

Hi all,
i've got some strange problem with my internet connection via dsl:
When I try to reach certain pages, I get a message in mozilla that tells me,
that the connection was refused by the peer. This happens only when i try to
reach some encrypted pages, such as www.elsterformular.de.
Now the curious part: When I establish the connection via isdn, everything
works fine!
I use IP Masquerading in both cases, and already tried to set the mtu for
dsl to 1412. My Kernel-Ver is 2.2, so the ECN disabling doesn't work for me
(tried it but didn't work).
If anyone got an idea what the problem could be, I would be very happy.