I have been using Invision for eons now and have never had any problems, up until now

Simply put, when anybody tries to get on my fserve (via any trigger) nothing happens their end and I get the following message in my 'Status' window...
* /fserve: unable to resolve local host (line 291, ialias2.mrc)
I have read several *apparent* ways to solve this, none of which seem to work.
I have removed my host address from - Tools/Options/Local Info - Local Host, and got it to find it again, but it keeps putting the same one back again (which has been fine up until now). If I put in my IP address, when I restart mIRC it just returns back to putting the host address in there instead of my IP address. I fail to see why I should have to use my IP as this has been working for the last few years without a problem

Any help would be muchy appreciated as ppl depend on my fserve (legal stuff before we open that can of worms).
Regards
Stef
P.S. Oh and btw, this is line 291 of ialias2.mrc.....
fserve $1 99 $shortfn($r.set( [ Fserve. [ $+ [ $2 ] ] ] ,Root.Dir)) $iif($isfile($shortfn($r.set( [ Fserve. [ $+ [ $2 ] ] ] ,Welcome.File))),$shortfn($r.set( [ Fserve. [ $+ [ $2 ] ] ] ,Welcome.File)))