Pol problem (bug?)

[Joerg Arndt <arndt@jjj.de>]

I do not see a system here:

? Pol([a,b,c])
a*x^2 + b*x + c
? Pol([a,b,c],d)
a*d^2 + b*d + c
? Pol([a,b,c],x)
a*x^2 + b*x + c
? Pol([a,x,c])
a*x^2 + x*x + c
? Pol([a,x,c],'x)
a*x^2 + x*x + c

? Pol([a,x,c],'x_)
  *** Pol: main variable has highest priority in gtopoly.
? Pol([a,x,c],'a_)
  *** Pol: main variable has highest priority in gtopoly.
? Pol([a,x,c],'z_)
  *** Pol: main variable has highest priority in gtopoly.

what is a "main variable"?

There does not seem to be a workaround.
Bad because it nukes my code when used with symbols.