Sounds kinda like uneven sugar.
The solution is: during the first week or so of primary, shake or stir the beer every now and then. Stop shaking a few days before bottling time. When bottling make sure the beer is mixed after you add the bottling sugar (though don't aerate/oxygenate it; use a sanitized spoon or something).
It shouldn't happen again, if you go that way. I think it was more the fact that you bottled the Grolsch bottles last and the sugar wasn't evenly distributed, rather than the fact that they are Grolsch bottles.