smartgwt + gwt-rpc or REST + spring-Collection of common programming errors

Hi I am currently working on a project and basing my design proposal on a SOA architecture and am including GWT components for UI . I am new to GWT and after reading through a week of posts of GWT and SmartGWT and trying out samples i would like to introduce SmartGWT into my organization w/o the server-side integration. That is because we already have spring services and would like them to remain re-usable through the organization. So my main interest is in the ui components of Smart GWT and in some fashion (either gwt-rpc or REST ) connect to the backend exposed services. I am developing on SmartGWT 2.4 and gwt2.2+ . I have gone through the posts on GWT-rpc and tried using the sample api presented. However i ran into a couple issues . Running the ListGridSample ‘as is’ i get the following ERROR although the application runs. Am using the sample from here

_{23:31:37.101 [ERROR] [listgridtest] 23:31:37.088:RDQ5:WARN:ResultSet:isc_ResultSet_0 (created by: isc_OID_1):get: invalid index -1 com.smartgwt.client.core.JsObject$SGWT_WARN: 23:31:37.088:RDQ5:WARN:ResultSet:isc_ResultSet_0 (created by: isc_OID_1):get: invalid index -1 at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:513) at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:105) at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71) at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:157) at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessages(BrowserChannelServer.java:281) at com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:531) at com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:352) at java.lang.Thread.run(Thread.java:619)}

I next wanted to remove all the redundant jars present in the example project and update the smartgwt jars and gwt-servlet jar to see if it is still compatible. I received this

_{23:37:06.584 [ERROR] [listgridtest] Unable to load module entry point class mytest.client.YourEntryPoint (see associated exception for details) com.google.gwt.core.client.JavaScriptException: (TypeError): Object [object Object] has no method ‘getNextGlobalIDForClass’ stack: TypeError: Object [object Object] has no method ‘getNextGlobalIDForClass’ at unknown source at __gwt_jsInvoke (ttp://127.0.0.1:8888/listgridtest/hosted.html?listgridtest:76:35) at ttp://127.0.0.1:8888/listgridtest/hosted.html?listgridtest:280:16 at z (ttp://127.0.0.1:8888/listgridtest/listgridtest.nocache.js:2:144) at ttp://127.0.0.1:8888/listgridtest/listgridtest.nocache.js:8:589 arguments: getNextGlobalIDForClass,[object Object] type: undefined_method __gwt_ObjectId: 2 at com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:237) at com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:129) at com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:561) at com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:269) at com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:91) at com.smartgwt.client.util.SC.generateID(SC.java) at com.smartgwt.client.widgets.BaseWidget.(BaseWidget.java:102) at com.smartgwt.client.widgets.Canvas.(Canvas.java:75) at mytest.client.YourEntryPoint.onModuleLoad(YourEntryPoint.java:24) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at com.google.gwt.dev.shell.ModuleSpace.onLoad(ModuleSpace.java:396) at com.google.gwt.dev.shell.OophmSessionHandler.loadModule(OophmSessionHandler.java:183) at com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:510) at com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:352) at java.lang.Thread.run(Thread.java:619)}

I read somewhere on the smartclient forums not to mix the smartgwtee and smartgwt jars so i double checked (because i was evaluating the ee edition b4this but that required a learning in the datasource concept ). So i am using gwt2.2+ and smart-gwt2.4.

I have read through the quick start pdf (quickly) and decided that although the server side integration may have benefits for a quick introduction within my organization it would not work. So from an system standpoint if i understand correctly you could define your datasource for your partricular widgets and then use the GenericGwtService to pass on to your business services before or after you send back the DSresponse. Can you kindly point me to a quick sample which actually does this in the latest version or a document which specifies exactly how to do it ? or an api or a forum post which addresses this for the latest versions. Hopefully that would help me springify the sample miniapp.. which would help me POC. Any input appreciated. Thanks,