[cem] cem error message

I am attempting to run cem with an ordinal treatment variable that has four values. I get the following error message: imbalance(): 3258 <tmp>[1,1] found where void required <istmt>: - function returned error r(3258); A previous reply to someone who also got this error message said to update cem because there was a bug with the imb function. I updated and now recieve this message: NOTE: Treatment has must have only 2 levels to compute distance and weights. In addition, k2k cannot be used. Does this mean cem cannot be used with more than 2 treatments? Actually I have a continuous treatment but I recoded it to a variable with four levels. Thanks! Erik -- Erik Cleven, PhD Assistant Professor Department of Politics Saint Anselm College 100 Saint Anselm Drive Manchester, NH 03102-1310 E-mail: ecleven(a)anselm.edu Office Phone: (603) 222-4119 Cell phone: (603) 867-8732