how to set transparent to false on wms query?

[Jaakko Kahkonen]

I'm trying to use mapserver 4.6 as a WMS client. When sniffing GET query
with ethereal, I noticed that query uses TRANSPARENT=TRUE value as a
default.

And WMS-server I'm quering does not support transparency:

<ServiceExceptionReport version="1.1.1">
<ServiceException code="OperationNotSupported">Request is for an
optional operation that is not supported by the server
 : Transparency of returned images not supported on this
version.</ServiceException>
</ServiceExceptionReport>

How can I send a query from mapserver without TRANSPARENT=TRUE value, or
does this reply from server mean something else? I tried to set
TRANSPARENT OFF, but it didn't help...

-- 
Jaakko