The ACT Party's two weeks of turmoil didn't affect the Government stability, and it is worth pointing that out because minor party meltdowns give MMP a bad name.
ACT was the first party to sign a support agreement with National after the 2008 election, adding its five votes to National's 58 for a total of 63, enough for a majority in the 122-member Parliament.
The agreement has been tested several times, but ACT has never even considered reneging on its deal.
Despite that, ACT's internal strife has again brought the role of minor parties under MMP into sharp focus and raised questions about the value of their contribution to the system of government that was introduced in 1996.
The "tails that wag the dog" have always been a target for opponents of MMP and they will be again during the campaign ahead of the referendum on the electoral system which will be held at the same time as next year's general election.
It isn't helpful to the supporters of proportional representation when any minor party, through its own actions, can be cited as an example of woeful indiscipline and questionable commitment to its own stability.
Voters will be asked in the referendum whether they want to retain MMP and to choose a preferred option from a list of other systems. Those who want to stay with MMP will be asked to choose a preferred option anyway.
If a majority want to change the system, a second referendum at the same time as the 2014 general election will run off MMP against the most popular preference from the first referendum.
The Government has said that if the first referendum delivers a majority in favour of retaining MMP, the system will be reviewed and changes to it are likely.
That brings up ACT again. It couldn't crack the 5 percent barrier under MMP to hold seats in Parliament, but it was given five because its leader, Rodney Hide, retained the Epsom electorate seat.
When that happens, a party doesn't have to reach 5 percent of the party vote and is given seats based on the proportion it did get - in ACT's case 3.65 percent gave it five.
This is one of the most criticised aspects of MMP and a typical attitude was expressed in an editorial published in the latest edition of the Sunday Star-Times.
"ACT has shown a flaw in the system," the paper said.
"Small parties which win an electorate seat can dodge the 5 percent parliamentary threshold and gain power they simply don't deserve to have.
"ACT came into Parliament with the backing of a mere 3.65 percent. This, truly, is the tail wagging the dog and the system must be changed to stop something similar happening again."
To support its "tail wagging the dog" complaint, the paper referred to ACT's involvement in extending the 90-day employment probation period to all businesses - something the minor party wanted, and gained, even though Labour Minister Kate Wilkinson had recommended extending the law to businesses with fewer than 50 employees because she considered big businesses have sufficiently sophisticated procedures not to need it.
The Sunday Star-Times had a lot more to say about ACT, but its point about the way the system works for minor parties which manage to win an electorate seat and gain up to five MPs without reaching the 5 percent threshold probably represents a widely-held view among voters.
It does need to be changed, or MMP will continue to be afflicted by negative attitudes caused by that one aspect of its operation.
That, however, can't happen until after the first referendum so it will be used to discredit MMP by those who want to change to another system.
ACT isn't the only party in the under 5 percent bracket. United Future's leader Peter Dunne holds the Ohariu seat and his party is also exempt from the threshold. In United Future's case it only won 0.87 percent of the party vote last time so it didn't qualify for more than one seat.
The Greens are a genuine MMP minor party with nine list seats from their 6.72 percent of the party vote, and no electorate seats.
The Maori Party is the opposite, holding five electorate seats with 2.39 percent of the party vote - a situation called overhang which resulted in 122 MPs instead of the usual 120.
ACT's case is open to criticism more than any other because Epsom was a National Party seat until it quietly allowed Hide to win it because it saw the need for a support party to give it a majority.
Hide has worked hard as an electorate MP and would claim to hold the seat in his own right, but there isn't much doubt National could take it away from him if it wanted to.
And it could decide to do that if it comes to the conclusion that ACT is more trouble than it is worth, and if its poll ratings are so small that it looks like falling into the United Future category with the prospect of having only one or two MPs in Parliament.
Under that scenario, National would be better off having one of its own MPs in the seat.
For these reasons, and for the sake of MMP itself, it is essential for ACT to behave itself between now and the next election.
If it doesn't, it isn't likely to return to Parliament and MMP will be the loser along with it.
NZPA