Hiccups from white methadone?

[Blue.. Like Water]

I searched but couldn't find anything on the matter. SWIM is a big methadone lover and has been doing it infrequently and in low levels on and off ever since late 2004. He has had peach wafers (40 mg) and the small round white pills (5-10mg.) Wafers never gave SWIM this problem, but the white pills give him horrible cases of the hiccups. A dose of white methadone even as low as 20 mg will have SWIM in bliss but the hiccups they give him are so bad that they are painful. They're extremely hard to get rid of and after being on the drug for several days straight the hiccups get so frustrating that SWIM had a slight freakout in public once. The kicker is that once the hiccups go away and SWIM has forgotten about them and gone about his business, they will come back full force the second SWIM even thinks about them. Has anyone else ever had this experience? Or is SWIM just unlucky?