Slovenia and Lake Bled licence myth or true ?.

Cajun Duo

Just spotted that you need a photo style driving licence to drive in Slovenia. We are planning on going to Lake Bled area next week so is this true and as I have the old style paper licence will I need a International Driving Permit. Has any body used a
IDP.AA and RAC give different advice also does the gov.co.uk site Also what the weather likely to be as we have seen that it can be wet in May.