Romance publisher Dreamspinner Press has four submission calls for stories of 3500 to 12,000 words. Payment is a flat rate based on the length of the story. The press pays an advance up to $1000 on novels and a good flat rate for novellas so the payment should be pretty close to professional rates. And here are the themes and deadlines:
1. Cuddling - rekindling romance, deadline April 1.
2. Steamed Up - romance with a steampunk theme, deadline July 1.
3. 2013 Advent Calander - heartwarming stories centered around the winter holidays, deadline August 1.
4. Dr. Feelgood - medicine/physical health theme, deadline October 1.
You can find all the details here for the calls here