I just repeated what the Irish Aviation Authority told me when I asked if I could fly into Waterford at night. They told me that under the "harmonisation" of JAR that the rules were the same as the UK.
You can file under Instrument Flight Rules without an IR provided you were clear of cloud etc and that you gained a Special VFR clearance to enter a control zone.
I cut and paste the contents of there email in my last post.
If that is not good enough then I suggest that instead of rumour that FS needs to contact them and get it in writing for himself.