The Simpsons movie is finally arriving in theatres near you. We waited almost two decades for this?

The Simpsons movie is neither a great film nor a terrible film. It is not a film you are going to want in your DVD collection for all of eternity. It is a fairly entertaining effort but also a little disappointing.

It is really not fair to compare a movie to its' television series. The TV series has numerous advantages, including shorter air time which allows for a faster pace. A two hour movie needs almost 120 minutes of story. Not all that easy to do. Comparisons  are not fair but compare we must.

The Simpsons movie suffers the same fate as two other popular series, Star Trek and Star Trek: Next Generation suffered when their respective movies came out: The films were just not that good.

If you compare the Simpsons movie with the ten or fifteen best Simpsons television episodes, the verdict is very clear: The TV episodes are better. Far better. The same goes for the Star Trek movies and TV shows. The movies just do not match the quality of the boob tube efforts.

Here's why. The Simpsons movie is consistently funny. The majority of jokes work although nothing has you howling and rolling on the sticky floor. The visual impact of the Simpsons and its' assorted characters is a striking improvement from the television show.

An important part of the Simpson success has always been the shows' sharp satire. That satire is on good display here, with numerous cultural references and even the Simpsons themselves being nicely harpooned. Big government takes repeated whacks, with the Environmental Protection Agency, the EPA, a recurring juicy target of the writers.

The ominous EPA helicopters and the agencies' apparent ability to launch nuclear attacks on Springfield after duping a nearly clueless President Arnold Schwarzenegger, the ultimate Terminator, is rich with political symbolism.

The movie has plenty of humor, satire and the usual stable of lovable loser characters. So what's wrong? The story is what's wrong.

The movie rolls along fairly nicely until Springfield is declared an environmental disaster, thanks to the bumbling ignorance of one Homer J. Simpson. The movie begins to slip from here.

The EPA's solution to the pollution nightmare is just too ridiculous. The climactic scene with Homer J riding to the towns' rescue is too much to believe. The Simpsons best work is when their stories are reasonably believable and often simple: Bart sells his soul to Milhouse for $5. Homer fears Bart is going gay. Krusty the Clown explores his Jewish heritage. The old writers' adage of simple plot, complex characters, is still valid. One risks much the further one wanders from it.

You suspend disbelief when you pick up a novel, go to a movie or attend a play. That is understood. It is a major reason we are attracted to fiction. That suspending of disbelief has its' limits. It cannot go too far. The story, in any genre, still has to maintain some sense of rationality and plausibility. The characters, no matter how crazy they may be, must still act in a believable manner consistent with the story line. Audiences will tune it all out if the characters' behavior does not make sense. "No, he wouldn't act like that. No way," is what they might say.

James Bond is expected to be cool, brave and sophisticated, no matter how precarious the situation. Change him into a touchy, feely Hawkeye Pierce or an indecisive Hamlet, and you got problems, baby, unless there is a valid explanation for the behavior. And it had better be a very valid explanation.

At the very least, the story has to have a decent ending. A slam-bang, kick butt finale is great, but not always a necessity. An ending that wraps things up in a believable manner, whether uplifting or depressing, is a necessity. A marginal story can be upgraded with a strong ending. A top notch story can be brought down with a poor ending.

Many film brainiacs consider Casablanca to be one of the greatest American films. It has a good story, attractive characters and an emotionally dynamite finish. Can you imagine if the writers and director had followed the original ending of the play on which the screenplay was based, with Rick ending up in a prisoner of war camp? The movie would never have been made.

This is what hurts the Simpsons movie. It is funny, satirical and nice to look at but ultimately a little disappointing because the story becomes too unbelievable (even for a cartoon) and the climax just does not ring true.

Is it worth seeing? Yes, particularly on a hot, humid afternoon with ten people in the wonderfully air conditioned theatre. Is it a must have for your bulging DVD collection?