I grew up in several countries, and had a really crazy time in school, twice I skipped a grade because I changed schools between countries, and twice I was held back a year. I was never in 7th or 9th grade, but twice in 8th and 11th, and in the grades with kids a year younger than me to 2 years older.
Do I have to worry about my children going through something similar if we change countries in the EU, or is school progress better regulated across boundaries nowadays. Like say university courses, with ECTS points that have to be reached in specific topics up to a certain year? Are there other countries outside of the EU which are similarly adjusted to switching between school systems?
Edit: to clarify, I mean all schooling systems before Higher Education (as in the graph in ppumpkin's answer).