hello
i had the same problem with PPPOE.
my provider is t-link.de.
first i had a login without the "#", but after a while i got a login of the same type as yours.
the problem and solution:
the pppoed gives the login in not-quoted version to the pppd, the pppd gets confused by the "#".
after googling a bit i found a new pppoe, the gives the login in quoted version to the pppd. now it works fine for me.
the new version is e-smith-rp-pppoe-1.8.0-02.
feel free to contact me per email, because i'm german.
cheers klaus