Issue using an unmanaged dll in a ASP.Net 2.0 Webservice

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Hi,



Any help with this problem would be greatly apprecicated as it is driving me
insane.



I have an ASP.NET 2.0 Webservice running on Windows server 2003. The
webservice calls a function in a legacy (unmanaged) C++ .dll which takes an
XML string and returns an XML string. It all works rather nicely most of the
time.



However, if the service isn't used for a while, when I call the function, I
get the old "Unable to load DLL" error. If I then restart the webservice, it
starts working again.



Here is my dll import declaration:



[DllImport(@"C:\GridVersion\CLibDll.dll", CallingConvention =
CallingConvention.StdCall)]


public static extern void calculateRequestFromDotNet(StringBuilder request,
StringBuilder response);





Any ideas on how I can even begin to resolve this issue would be
really,really appreciated.



Many thanks



Rob

.

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