Question About Melbourne, Peel, and the Ladies-In-Waiting Thing

Could somebody who knows British history very, very well please answer this question?

In this film, we see the Bedchamber Crisis of 1839 as being triggered by Melbourne's allegedly "losing the election," which some other posters on these threads seem to think is accurate.

But there was no general election in 1839, not until 1841. In 1839, the Whigs still held a slim majority in Commons, even after they lost seats in 1837, the first election of Victoria's reign.

All that The Wiki Of Life says about it is "(i)n May 1839, Melbourne's resignation led to the Bedchamber Crisis." ( http://en.wikipedia.org/wiki/William_Lamb,_2nd_Viscount_Melbourne )

Presumably, Victoria then refused to accept Melbourne's resignation if it meant Peel* would be allowed to force her to discharge any of her ladies-in-waiting.

So... what am I missing here? Why did Melbourne suddenly try to resign in 1839?

Brits, please don't fault me too much for not knowing this one. I'm an American who is inevitably sometimes puzzled by some of the finer points of history across the pond, and I can't afford to buy a bunch of history books to track this one down-- especially since I wouldn't have a clue which book to look in.

*As I imagine it, Peel probably didn't all that much want to be PM at the time, if that meant heading up a minority-party rule.

"I don't deduce, I observe."