This is a rather big change, so I have to make a note of it here.
Anyways, the URLs have been changed so they look "pretty". It's no longer some complicated topic=456.34? etc. This means that you have to update *all* links that you've posted before if you want to keep them to work. Sorry for the inconvenience but this is a step for better SE Optimization.
Edit, just checked, the old URLs still work apparently.