We consider Lebesgue-integrable, compactly supported solutions of two-
scale difference equations and investigate the relations between trans
lates of these solutions. A detailed study of corresponding invariant
subspaces leads to new observations concerning the factorization of th
e refinement mask and certain spectral properties of corresponding coe
fficient matrices. In particular, new necessary conditions for the exi
stence of integrable, compactly supported solutions are derived. (C) 1
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