The smart url detector should first see if it matches a pattern and if yes, see if that pattern actually contains an active language of the system, and only remove it from the URL in that case. So if /ds/ does not correspond to a real language that is also activated on the system then there shouldn't be a problem.
So this might still be a cause for confusion but not as serious as if it would be when all top-level two-letter URL's were disabled.
