Where is BTRavenn when we need him most. What I have learned from the internet.
It is very rare for a speaker to have to vote to break a tie. It has happened 11 times federally. Five of those times were by Peter Milligan, a Liberal, who was Speaker of the House when Paul Martin was PM but was so popular with all members that he continued as speaker when Harper led his minorities.
Again, this is federally, but I read that the Speaker generally votes with the government out of convention. I am not sure where that convention comes from. As wmcduff points out the speaker generally is a member of the governing party so that explains a lot, but I also believe the convention only applies to votes of confidence. In other words he or she votes to maintain the status quo. I don't believe there is a convention on other votes so the speaker could vote against the government on any legislation except the budget.
Of course I might be wrong. I suggest Jabber63 link us to something more substantial than my google searches.
Whatever the situation I suppose now that Jabber63 has pulled a Donald Trump and leaked the plot, the opposition members can refuse to be speaker and until a speaker is chosen nothing and I mean nothing (including a Throne Speech) can proceed.