Cannot find mono.exe . How to change Mono path for stand-alone build?

Hi there,

I'm adding Magento support to our Unity project (uses System.Web.Services). It's working in the editor but when I run a build the Mono path is targeting my local user directory (I've added some output form the log below). Is there any way within Unity to ensure that the build has access to mono.exe?
Thanks for any help.

Mono path[0] = 'C:/Users/#user#/Projects/Folder/MagentoTest4/Builds/MagentoTest_Data/Managed'
Mono config path = 'C:/Users/#user#/Projects/Folder/MagentoTest4/Builds/MonoBleedingEdge/etc'
PlayerConnection initialized from C:/Users/#user#/Projects/Folder/MagentoTest4/Builds/MagentoTest_Data (debug = 0)
PlayerConnection initialized network socket : 0.0.0.0 #####
...
SystemException: Error running C:\Users\#user#\Projects\Folder\mono\mini\mono.exe: The system cannot find the file specified.
at Microsoft.CSharp.CSharpCodeGenerator.FromFileBatch (System.CodeDom.Compiler.CompilerParameters options, System.String[] fileNames) [0x00160] in <ac210d81537245bc838518cc8e845861>:0
at Microsoft.CSharp.CSharpCodeGenerator.FromSourceBatch (System.CodeDom.Compiler.CompilerParameters options, System.String[] sources) [0x00094] in <ac210d81537245bc838518cc8e845861>:0
at Microsoft.CSharp.CSharpCodeGenerator.System.CodeDom.Compiler.ICodeCompiler.CompileAssemblyFromSourceBatch (System.CodeDom.Compiler.CompilerParameters options, System.String[] sources) [0x0000f] in <ac210d81537245bc838518cc8e845861>:0
at System.CodeDom.Compiler.CodeDomProvider.CompileAssemblyFromSource (System.CodeDom.Compiler.CompilerParameters options, System.String[] sources) [0x00006] in <ac210d81537245bc838518cc8e845861>:0
...