failing to explore multiple records of two tables with READ service

Hi,

I am failing to provide records within two tables via a Gateway service.

In ERP:

• I have written a RFC that has a single Import-Paramter and returns two tables (defined in 'Tables' tab)
• For testing purposes, I inserted two records for each of the table. (hard coded)

In Gateway:

• I have developed a READ service
• executing the metadata request http://<host>:8000/sap/opu/odata/sap/ZANDREASEXPORTC/$metadata works fine and the metadata document is attached.
• executing the READ operation http://<host>:8000/sap/opu/odata/sap/ZANDREASEXPORTC/z_andreas_export_cCollection(i_input='111')  looks also fine:

<entry xml:base="http://<host>:8000/sap/opu/odata/sap/ZANDREASEXPORTC/">
     <id>http://<host>:8000/sap/opu/odata/sap/ZANDREASEXPORTC/z_andreas_export_cCollection('111')</id>
     <title type="text">z_andreas_export_cCollection('111')</title>
     <updated>2013-06-05T07:51:09Z</updated>
     <category term="ZANDREASEXPORTC.z_andreas_export_c" scheme="http://schemas.microsoft.com/ado/2007/08/dataservices/scheme"/>
     <link href="z_andreas_export_cCollection('111')" rel="self" title="z_andreas_export_c"/>
     <link href="z_andreas_export_cCollection('111')/e_specific_r" rel="http://schemas.microsoft.com/ado/2007/08/dataservices/related/e_specific_r" type="application/atom+xml;type=feed" title="e_specific_r"/>
<link href="z_andreas_export_cCollection('111')/e_general_r" rel="http://schemas.microsoft.com/ado/2007/08/dataservices/related/e_general_r" type="application/atom+xml;type=feed" title="e_general_r"/>
<content type="application/xml">
<m:properties>
<d:i_input>111</d:i_input>
</m:properties>
</content>
</entry>

My expectation was that the following URL would provide the records of one of the tables:

http://<host>:8000/sap/opu/odata/sap/ZANDREASEXPORTC/z_andreas_export_cCollection('111')/e_specific_r

But I got an error:

<error>
<code>/IWFND/MC_ODC_COE_U/003</code>
<message xml:lang="en">Processing of request failed. Contact your system administrator</message>
<innererror>
<transactionid>A1C9CDE2A851F12DB57122000AF84904</transactionid>
<errordetails/>
</innererror>
</error>

Looking into the Gateway ERROR LOG I gathered the following information:

• T100 Error ID:    /IWFND/MC_ODC_COE_AD001
• Error Text:          Operation type Q does not exist in the Data Model
• Component:    OPU-GW-LCP

Why does this error occur?