wine users - Mar 2001 - Opposing Force

I have installed Half-Life and updated it with the latest patch (1.1.0.4). It
runs fine. I installed Opposing Force and updated it with the
latest patch (1.1.0.4) and can 'activiate' it from the Half-Life
'Custom' menu, but as soon as I try to customise it or play it, it gives
an error and crashes :-(

Am I doing something wrong?

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