I don't know why you signed up with "talkabout network" to access this
public usenet newsgroup (alt.autos.citroen).  Assuming that your email
address really is virgin.net [1] that means that your ISP is probably
Virginmedia.com (formerly NTL, mostly) and they provide a proper
news-server for their customers; you can read about it by going to
<http://www.virginmedia.com/customers/> and clicking on 'Newsgroups' in
the menu on the left.  

Once set up, newsgroups are much easier to read and post to using a real
news-server than going via a web site that pretends to be a private web
forum.

You can even read and post to this newsgroup using Google Groups, who are
at least less coy about admitting that they are exploiting usenet.  See
<http://groups.google.com/group/alt.autos.citroen/topics>.

As for your vanishing oil, perhaps you should get a mechanic to take a look
at the engine and the dipstick - if it isn't going up in smoke from the
exhaust pipe, it isn't impossible that you aren't pushing the dipstick
fully 'home', or that it is broken short or the wrong one for your car
(whatever that might be).  

Presumably you are making sure that the car is on level ground when you
check the oil ...

[1] Everybody can see that, apart from those (very very few) using the
talkabout web site to read this group; the [EMAIL PROTECTED] you can see
counts for precisely nothing.