What is ill founded by this claim by Sir William Ramsay (and the other one by Ernest Martin) in the article cited earlier?
From the article:
"The second option is favored by William Ramsey (NBD, s.v. "Quirinius"):
"The possibility that Quirinius may have been governor of Syria on an earlier occasion (*Chronology of the NT) has found confirmation in the eyes of a number of scholars (especially W. M. Ramsay) from the testimony of the Lapis Tiburtinus (CIL, 14. 3613). This inscription, recording the career of a distinguished Roman officer, is unfortunately mutilated, so that the officer’s name is missing, but from the details that survive he could very well be Quirinius. It contains a statement that when he became imperial legate of Syria he entered upon that office ‘for the second time’ (Lat. iterum). The question is: did he become imperial legate of Syria for the second time, or did he simply receive an imperial legateship for the second time, having governed another province in that capacity on the earlier occasion?...The wording is ambiguous. Ramsay held that he was appointed an additional legate of Syria between 10 and 7 bc, for the purpose of conducting the Homanadensian war, while the civil administration of the province was in the hands of other governors, including Sentius Saturninus (8-6 bc), under whom, according to Tertullian (Adv. Marc. 4. 19), the census of Lk. 2:1ff. was held."
Under either of these scenarios, SOMEONE served twice, and under either of these scenarios, Quirinius could EASILY have been responsible for the census."
http://www.christian-thinktank.com/quirinius.html