Benny and Dave are both right, because there are dangers on both sides of the argument. If there is compulsory voting we may indeed, as I believe we do currently, have a whole bunch of people voting who have not the slightest idea about the policies and ideology of the political party they are voting for. In America for example it seems (I can reference this if anyone asks) that only 3% of people vote and express opinions that is consistent with an ideology and that do not continually contradict themselves; that is, there is a whole bunch of voters who don't think through their decisions in much depth. This is a problem. I think this best supports Benny's argument because not only is it correct that we should be able to exercise our right or not, but we don't want a whole lot of apathetic, uneducated voters and voters who cannot see past their own selfish affairs. Essentially, democracy becomes a farce at this point; a popularity contest over which the mainstream media exercise considerable influence - a big danger.
Dave puts forward an equally powerful argument: how can we guard ourselves from the outcomes of class? This is not an equal playing field, so democracy, when everyone participates, seems to level the field because everyone is equal to just one vote and everyone has to vote so it eliminates the likelihood that there will be more representation from specific classes.
To me, there are pitfalls on both sides. The common problem is the uneducated, irrational voter. This is why I believe that universal education, health care and other forms of social support that reduce the effects of stratification and inequality are important if we want to stimulate a rational democracy.
If we have such an educated democratic society, it should not matter whether voting is compulsory or not because people will most probably want to and if not, we can count on that decision being a more thought out choice than otherwise would be the case.

Dammit you guys, every time I decide on an opinion one of you posts and makes it harder for me to stick with that opinion.    At the moment I'm more for the compulsory voting side, though.  Although you're totally right, RevolutionByNight (hey that rhymed) that there are definitely pitfalls on both sides. 

But then again there's always a downside to everything in politics.  I'm sure there are some left-wing values that not all left-wingers agree with and the same with the right-wingers.  Like an anti-war supporter who doesn't believe in gay marriage.  Pretty crappy and general example but you get the idea.