Slightly strange thing happens here. The Dutch have an enormous army outside one of my cities, on this turn I withdrew all defenders and the next turn the Dutch withdrew instead of taking the city.
City name is Lingupura, just withdraw the units from the city and click through the rest on this turn.
This is a known bug with the V23 release that was subsequently fixed. What version are you using? If it's SVN or V24 release please post an illustratrive save game that reproduces the issue.