Querying Customer Lists

I want to query a custom list via Web Services. I am following the example on page 151 of the Web Services Records user guide (version 1.3.2). The same example was also presented in the old user forum as well, as follows.

CustomRecordSearch customRecordSearch = new CustomRecordSearch();
RecordRef recordRef = new RecordRef();
recordRef.setInternalId("3");
customRecordSearch.setRecType(recordRef);
SearchResult result = port.search(customRecordSearch);

I am using the internal id "3" obtained from my custom lists' URL:
https://system.netsuite.com/app/common/custom/custlist.nl?id=3&e=T&ord=F
I am also using CustomRecordSearchBasic in place of CustomRecordSearch in the 1.3.2 WSDL.

When I run this code I get back a failed status Code = USER_ERROR, Message = Invalid Record Type.