There are a number of caveats with this article, relatively small sample size, picking a trend out from a stampede, etc., but this is unsurprising:
Exit polling commissioned by the major cable news networks has found that 31% of people who identified as gay, lesbian or bisexual voted for Republicans on Election Day. That represents a big uptick from the 24% of gays who voted for the GOP in 2006 and from only 19% who did so in 2008. The trend appears to bear out pre-Election Day predictions from gay rights organizers that gay voters were angry and disenchanted with Democrats for not delivering on promises to the community
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(UPDATE: After reviewing the full data, Sherrill says there was a disproportionate drop in Democratic support among LGB voters compared to Hispanic, black, and young voters. Though the sample size is still very small and thus there's a large margin of error, Sherrill now says the drop may be attributed to "dissatisfaction with the pace of change on LGB rights over the past two years.")
(more after break)
It's more than dissatisfaction on DADT and DOMA, it's also things like aggressively appealing court rulings against DADT , allowing bigoted officers to continue their witch-hunts in the military, refusing to issue a n executive order to end separations, and refusing to provide spousal benefits to people who are legally married in gay marriage states.
Even if one believes that the Obama administration actually supports LGBT civil rights in theory, it would be tough not to conclude that they have no interest in doing so in practice.
The tragedy of this that doing the right thing here would have also been the right thing to do politically: there are a number of house races, and possibly 2 senate races that would have flipped to D if the Gay vote was at 2008 proportions.