[Serusers] @to.tag="" not detecting empty To tag?

Hi folks, I am moving production to SER2 rc 2.0 and can not make @to.tag=="" to work. For example, in initial INVITEs: # if this is an initial INVITE (without a To-tag) we might try another # (forwarding or voicemail) target after receiving an error if (method=="INVITE" && @to.tag=="") { xlog("L_ERR","LXLOG: initial INVITE (no Totag) setting FAILURE_ROUTE"); t_on_failure("FAILURE_ROUTE"); } FAILURE_ROUTE is never called. While next check works (in the sense the failure route is processed). if (method=="INVITE") { xlog("L_ERR","LXLOG: INVITE setting FAILURE_ROUTE"); t_on_failure("FAILURE_ROUTE"); } So I am wondering whether @to.tag=="" works for empty To tag....can anyone confirm it? Thanks, Samuel.