Immigration: known unknowns

The Home Office is on the rack because of the Daily Mail story that it knew that there was a problem with the unknown number of illegal immigrants (we don’t know how many there are of those) working in security jobs and didn’t tell us. Home Secretary Jacqui Smith claims she was waiting until she had better information. Is she simply very patient, spinning us, or has she found a way through the usual cock-up>>cover-up>>leak>>meltdown sequence that has deviled the Home Office over the last few years?