Ok I managed to figure out that the web.config setting didn't allow Anonymous access to the Webservices folder (might be an idea to set that as a default since it seems to be required) but now I'm getting another error which I have no idea how to solve:

Service1 Message 3 Error:
System.ServiceModel.FaultException: System.Web.Services.Protocols.SoapException: Server was unable to process request. ---> System.InvalidOperationException: Unable to generate a temporary class (result=1).
error CS0272: The property or indexer 'EPiServer.Core.LanguageSelector.SelectionSource' cannot be used in this context because the set accessor is inaccessible

   at System.Xml.Serialization.Compiler.Compile(Assembly parent, String ns, XmlSerializerCompilerParameters xmlParameters, Evidence evidence)
   at System.Xml.Serialization.TempAssembly.GenerateAssembly(XmlMapping[] xmlMappings, Type[] types, String defaultNamespace, Evidence evidence, XmlSerializerCompilerParameters parameters, Assembly assembly, Hashtable assemblies)
   at System.Xml.Serialization.TempAssembly..ctor(XmlMapping[] xmlMappings, Type[] types, String defaultNamespace, String location, Evidence evidence)
   at System.Xml.Serialization.XmlSerializer.FromMappings(XmlMapping[] mappings, Type type)
   at System.Web.Services.Protocols.SoapServerType..ctor(Type type, WebServiceProtocols protocolsSupported)
   at System.Web.Services.Protocols.SoapServerProtocol.Initialize()
   at System.Web.Services.Protocols.ServerProtocolFactory.Create(Type type, HttpContext context, HttpRequest request, HttpResponse response, Boolean& abortProcessing)
   --- End of inner exception stack trace ---

Server stack trace: 
   at System.ServiceModel.Channels.ServiceChannel.HandleReply(ProxyOperationRuntime operation, ProxyRpc& rpc)
   at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
   at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)

Exception rethrown at [0]: 
   at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
   at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
   at IntranetMailer.PageStoreService.PageStoreServiceSoap.GetDefaultPageData(GetDefaultPageDataRequest request)
   at IntranetMailer.PageStoreService.PageStoreServiceSoapClient.IntranetMailer.PageStoreService.PageStoreServiceSoap.GetDefaultPageData(GetDefaultPageDataRequest request) in C:\Source\PH\Intranet\IntranetMailer\Service References\PageStoreService\Reference.cs:line 2191
   at IntranetMailer.PageStoreService.PageStoreServiceSoapClient.GetDefaultPageData(PageReference parentPageLink, Int32 pageTypeID, LanguageSelector selector, AccessLevel access) in C:\Source\PH\Intranet\IntranetMailer\Service References\PageStoreService\Reference.cs:line 2201
   at IntranetMailer.IntranetMailerService.ProcessEmails() in C:\Source\PH\Intranet\IntranetMailer\IntranetMailerService.cs:line 94

 Any ideas at all would be most welcome

This is the code:

                        PageStoreServiceSoapClient pageStoreService = new PageStoreServiceSoapClient();
                        pageStoreService.ClientCredentials.UserName.UserName = "user";
                        pageStoreService.ClientCredentials.UserName.Password = "password";
                        PageReference reference = new PageReference { ID = 24 };
                        LanguageSelector selector = new LanguageSelector { LanguageBranch = "en-GB" };
                        RawPage rawPage = pageStoreService.GetDefaultPageData(reference, 6, selector, AccessLevel.Create);

It fails on trying to create the RawPage

Anyone?

Try changing security mode to "TransportCredentialOnly" if you have not fixed it yet.

<security mode="TransportCredentialOnly">
                        <transport clientCredentialType="Basic" proxyCredentialType="None"
                            realm="" />
                    </security>

I think we have a bug for this one:

Bug #72114: Runtime compiler error CS0272 when using the PageStoreService 

I am having this problem with CMS 6 R2, the bug should be fixed in that version right? I am just trying to retrieve a page by ID. Has anyone found a workaround for this?

Kevin: It should be fixed in the general hotfix. Do you have that installed?

I'm not sure on that (I didn't set up the server), but I will check. Where is this hotfix available, in case that is the problem?

The EPiServer CMS 6 R2 release on world is the general hotfix. See this blog for more details (how to upgrade to it):

http://world.episerver.com/Blogs/Shahid-Nawaz/Dates/2012/1/General-Hotfix-CMS-6-R2/