Searching by ExternalId problem

Hi,

We're having problems searching by externalId when the string contains whitespace.  We're receiving an INVALID_KEY_OR_REF error stating the the externalId is invalid.

Should the following not work?

                SearchMultiSelectField extId = new SearchMultiSelectField();                 extId.setOperator(SearchMultiSelectFieldOperator.anyOf);                   RecordRef[] recordRefs = new RecordRef[1];                            RecordRef recordRef = new RecordRef();                          recordRef.setExternalId("Customer External Id");                          recordRefs[0] = recordRef;                            extId.setSearchValue(recordRefs);                          custSearchBasic.setExternalId(extId);