Memory problems with dbcmd

Dear all,

unfortunately, searching on google seemed to be unsuccessful for this, and
I didn't find any help looking ad previous discussions (maybe since I
subscribed this mailing list).

I have manage to set up a connection to a MS SQL database server using
freeTDS, but it sometimes (seldom, fortunately) happens that a dbcmd fails.
Looking at the various documentations, it should be a problem of memory
allocation, but this happened even for extremely simple queries like a
"begin transaction", and not always for the same query: it just happened in
a given moment, and it was not either possible to reproduce this problem,
but I remained afraid that it can appear again.
I don't really understand how can dbcmd fail with such a simple query when
the machine is not stuck (which I would think if it is a problem is so
serious that even such a small string cannot be allocated).

The MS SQL server stays in another machine to which I must connect through
network, although it is a machine internal to the location where all this
stuff runs. Can it happen that a sudden and momentary communication failure
causes dbcmd() to fail? Or its failure are only due to memory allocation
problems?

Is there any way I can adopt to deeper check this problem?

Thanks

Alberto