ON CALL Welcome to another installment of On Call, our weekly reader-contributed column that shares your stories of tech support jobs that tested your skill, sanity, and sensibilities. This week, meet a reader we'll Regomize as "Nathan" who told us that back in the mists of time, he worked for a small investment company. "Its sole purpose was, and probably remains, managing the European investments of a very rich Russian oligarch who shall remain nameless," Nathan told On Call. As befitted the oligarch's wealth, the firm's premises featured an elaborate entrance foyer with a standout feature Nathan described as "a magnificent chandelier suspended from the ceiling with a clockwork mechanism to lower it down for cleaning." Chandeliers don't need to be cleaned every day, but after cleaners got around to the job, an entire floor of the firm lost all network access – WAN and LAN were both deader than Lenin.…