They found that having a feminist partner was linked to healthier heterosexual relationships for women. Men with feminist partners also reported both more stable relationships and greater sexual satisfaction. According to these results, feminism does not predict poor romantic relationships but is actually the opposite.
The authors also tested the validity of feminist stereotypical beliefs amongst their two samples, based on the hypothesis that if feminist stereotypes are accurate, feminist women should be more likely to report themselves as being single, lesbian, or sexually unattractive than non-feminist women.
Their study reported that feminist women were more likely to be in a heterosexual romantic relationship than non-feminist women. The authors conclude that feminist stereotypes appear to be inaccurate, and therefore their unfavorable implications for relationships are also likely to be unfounded.
It's unfortunate, though perhaps not surprising, that the study focused on self-identified hetero's. It's also unfortunate that I can't seem to find the study itself online (if anybody can, I'd greatly appreciate a link). But it's a happy thing that somebody is even doing research on this stuff...and it doesn't hurt that the results seem promising to those of us who count ourselves as feminists, or feminist allies.