Plesk PHP Problem

[stuartp44]

Hey everyone, couldnt find any info on this problem i have. I have had this software for about a week now and its great the only problem is webmail, that hasnt been my main worrie but what is worring me is the running PHP as a ISAPI (i think thats what it is called) anyhow is the a way i can make that a default for creating accounts because the last thing i want to be doing is everytime a new user signs up i have to change this setting to let them use php correctly, anyhow the problem i used to get with them before i made the domain that are currently on my account run php extenstention as a aspi, but of course i cant do that with the webmail domain(default template) how can i fix this problem, all i seem to get is a HTTP 400 ERROR and i really could do with webmail working (horde).

http://webmail.homenetwork.me.uk/ < - See for your self

hope i have made myself clear and not confusing fook (I am smashing for that lol)

Stuart