I have tried the myadsl.mweb.co.za but it keeps on asking me to register, yet I accessed it last month with a bit of trial and error - too bad I can't remember how .
Something I learnt is that MWEB passwords can be a maximum of 8 characters in length, but when you initially set your password, it lets you make it as long as you want. This doesn't effect logging in via the web interface but does when connecting using your router.