Before the main feature begins, she would see the audience shoot to its feet and stand rigid as Thailand's national anthem blasts out and a short film is screened, showing King Bhumibol Adulyadej and Queen Sirikit. Thai society's normally relaxed air rapidly gives way to rigid formality where the monarchy is concerned. The ceremonial has been especially stifling this year, as King Bhumibol celebrates 50 years on the throne - the longest reign in the world.
Thais are proud of the continuity of the Chakri dynasty, which virtually created the country in the 18th century, and of the fact that they remained independent in the 19th century, while European powers were colonising their neighbours. Yet the extraordinary reverence shown to the royal family is relatively new, and certainly did not exist when King Bhumibol took the throne half a century ago. It is recognition of the fact that he has steered Thailand through a period of tremendous change, during which it has become one of the world's fastest-growing economies despite 17 military coups, 21 prime ministers and 15 revised constitutions.
But the 68-year-old King hasrecently undergone heart surgery,and eyes are turning to the succession. Like our own Queen,King Bhumibol has problems with his children.
The heir apparent is the tall, 44-year-old Crown Prince Maha Vajiralongkorn, who looks like a hard-punching pugilist and is said to hold authoritarian views. Closely identified with the military, the Prince loves fast cars and has a roving eye. Thais are uncomfortable about the fact that he lives openly with a "second wife", with whom he has had five children.
The unpopularity of the heir is demonstrated in a typically oblique way. Thais display pictures of the King and his highly-respected second daughter, Princess Maha Chakri Sirindhorn, in their houses and offices, whereas the Crown Prince's portrait is rarely seen outside official buildings. Earlier this year the Thai press, which lives in fear of tough lese majeste laws, gave prominence to reports that the Prince's chief aide-de-camp had been dismissed and sent into exile. No reasons were given.
The Prince has tried to repair his negative image, but his first effort at doing so simply worsened the damage. At a semi-formal reception for journalists he denied being a crime godfather and "providing protection for sleazy business" - allegations which none of the journalists would have dared voice themselves.
An amendment to the constitution appeared to make it possible for a female successor to take the throne, but royal watchers believe this is unlikely, even though the unmarried Princess Maha Chakri Sirindhorn, 41, would be welcomed by many. Her elder sister is ruled out because she married an American.
In this uncertainty, Thais can only console themselves that King Bhumibol looked equally unpromising when he took over in 1946. As with some of the most successful British monarchs, he came to the throne unexpectedly. His father died when he was two, and his uncle abdicated because he could not stomach the constraints placed on the palace by the military, which launched a bloodless coup in 1935 to end the absolute monarchy. This left Bhumibol's delicate 10-year-old elder brother to assume the throne, but King Anand Mahidol was shot dead at the royal palace in Bangkok, an incident which remains shrouded in mystery.
When the young monarch returned from Switzerland, he seemed very much a playboymore skilled at playing the saxophone and clarinet than at statecraft. But Field Marshal Sarit Thanarat, who seized power in 1957, encouraged him to take a more active role, hoping it would lend legitimacy to the regime.
The King seized his opportunity, travelling all over Thailand to initiate development projects and appear at religious ceremonies. The ninth member of the Chakri dynasty has remained a point of stability at a time of frantic modernisation, and now occupies a place in Thai society similar to his revered predecessor, Rama IV - immortalised in The King and I.
Bhumibol stopped Thailand's worst political bloodshed of recent times, the 1992 confrontation between the army and democracy protesters in Bangkok, by ordering the two principal antagonists to his palace. Television showed them crawling towards him and kneeling as they were admonished and told to restore peace. His word was enough: the government resigned and democracy protests dissolved.
The days may be long past when the British monarch could wield such power, but, after Bhumibol, the Chakri dynasty itself could be heading for as much trouble as the Windsors.