there was no inactivity by the legislature.
There were two votes by the state legislature (ordered by the same state supreme court that ruled the ban on gay marriage was unconstitutional).
A vote to amend the state constitution to ban gay marriage was successfully passed in the first session, but was defeated (narrowly), in the second session.
Had it passed the second time, it would have been left to the voters to decide...
"First Constitutional Convention vote
The first Constitutional Convention vote on the petition amendment was scheduled for July 12, 2006,<11> but was postponed until November 9, 2006 to take place after the next state elections.<12> On November 9th, 2006 the Legislature voted to recess the Constitutional Convention until January 2.
On November 19, 2006, Gov. Mitt Romney led a rally against the tactics that the Massachusetts legislature used to delay and possibly prevent a vote on the same-sex marriage ballot initiative in front of the Massachusetts State House. Romney said he would ask a justice of the state Supreme Judicial Court that week to put the initiative on the ballot in case the legislators failed to vote on the initiative on the last day of the Joint Session, January 2, 2007 as required by the Massachusetts Constitution Amendments Article XLVIII (The Initiative, IV. Legislative Action on Proposed Amendments, Section 2. Joint Session)<13> Romney said, "The issue before us is not whether same-sex couples should marry. The issue before us today is whether 109 legislators will follow the constitution."
On December 27, 2006, the Massachusetts Supreme Judicial Court agreed unanimously with Gov. Mitt Romney's repeated assertion that Article 48 of the Massachusetts Constitution explicitly and unambiguously requires that the Massachusetts Legislature take a final vote on any and all voter initiatives placed before them. That includes the marriage amendment. The court, though, also stated that it had no legal remedy that it could enforce upon the Legislature due to laws that separate the judicial and legislative branches of government.<14> The legislature voted on the measure on January 2, 2007, shortly before its 2005-2006 session ended. The amendment received 62 "for" votes in Constitutional Convention and thereby cleared its first hurdle toward ratification.<15> However, a second vote during the 2007-2008 session was needed to put the amendment to the voters."
http://en.wikipedia.org/wiki/Same-sex_marriage_in_Massachusetts#Attempts_to_amend_the_state_constitution