Due to their phosphate-groups the DNA-fragments are heavily negative charged molecules.
Because of that the silver-staining protocols are normally short and the perfomancesare without any problems.
But one mistake should not be done:
The first step, the fixing procedure, should not be to weak and/or to short:
The smaller DNA-fragments will then be not immobilized enough and they will be not in the gel anymore when the development step is performed. See the 2 pictures below.
Additional advantage is that recipes with this fixing step will stain all gel-types also these including 7 M Urea!