I'm experiencing the same condition. There is a small amount of yellowish globby stuff mixed in with the ejaculate and orgasm seems to be "thwarted" a bit by a very mild burning/painful sensation.
I've experienced the same condition several years ago when I began taking propecia, I stopped the medication immediately & it went away.
I've recently been taking an additional multivitamin containing ginkobiloba & other "mood stimulators" which i've also stopped taking a few days ago, i'm assuming it's causing this problem again...
Incidentally i'm on a small daily dose of prozac & have been for several years, it doesn't seem to have any affect on orgasm or the quality of semen. Perhaps a mixture of these vitamins & medications exacerbate this problem?