st: Error r(103) after gengroup command

[R Chase <rchase@jhsph.edu>]

I have not found mention of this error elsewhere, so perhaps I am
making a mistake.
I am using Stata 11.2 on Windows 7.
I have 3 categorical variables (A1, A3, and A6) with 5 categories each
(represented with integers 0 through 4) plus a missing value of .d.
Here is the command and the error I am getting:
. gengroup A1 A3 A6
 too many variables specified
 r(103);

The command works perfectly if I specify only one variable to group
by, such as A1.
If this were a problem others were having, I'd expect to see some
posts on it, but I can't find any.
Any ideas on what I am doing wrong?

~ Rachel Chase
Johns Hopkins Bloomberg School of Public Health, doctoral student
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