The algorithm used to hash a ScaledDecimal object changed in VisualAge Smalltalk V6.0.1. This change affects existing collections that rely on the hash value. The affected collections are, at least,

If your application uses ScaledDecimal objects as keys for any of these hashed collections, you must recompute the hash values after installing the current version of VA Smalltalk and before modifying the collection in any way. To recompute the hash values, send the rehash message to the collection for example,