JAR-FCL 1.065(a) states "An applicant shall demonstrate the satisfactory completion of all requirements for licence issue to the Authority of the ‘State of licence issue’" while JAR-FCL 1.065(c) states "Further ratings may be obtained under JAR–FCL requirements in any JAA Member State and will be entered into the licence by the State of licence issue."
It is clear that the line taken by the Norwegian CAA is not compliant with JAR-FCL as the IR is, by definition, a rating, whether or not some bureaucrat considers it to be a part of basic training. However, JARs are only 'Requirements' and JAA member states are free to pick and choose which they will comply with - just as other member states are free to refuse to accept licences and ratings where their issue has not been compliant with JAR-FCL as they interpret it (e.g. France and Spain frequently refuse to accept ratings where the training has been conducted outside of the JAA). This should all go away when EASA takes responsibility for ops and licensing in a couple of years time when EASA standards have the force of EU law(although since Norway is not a member of the EU it may still refuse to comply).
It is doubtful that the UK CAA will be very keen on coming to any arrangement with the Spanish authority, judging by the opinions expressed recently by one of their senior staff examiners. The conduct of Spanish training and testing, especially for the IR and FI, does not seem to be held in particularly high regard in the UK.