CAML-Query external List

Question

Hi,
I am just wondering if there is a limitation on using the <IN>-tag in a CAML-Query on external lists. Whenever I try to use it, I get this error:
Original error: Microsoft.SharePoint.SPException: Search could not be performed. The underlying CAML query could not be executed. 
The syntax I am using:
<In>
    <FieldRef Name='FieldName' />
    <Values>
      <Value Type='Integer'>1</Value>
      <Value Type='Integer'>2</Value>
    </Values>
  </In>
should be correct, as I am testing this with a caml-builder also. When using IN on a normal sharepoint-list using the same
syntax and tools I get my desired results.

Answer 1

Taken out, and still nope. i'm getting no errors it's just showing everything in the list
Ben
Private Sub BindPersonCAML()
Dim siteURL As String = SPContext.Current.Web.Url
Using oSiteCollection As New SPSite(siteURL)
Using oWebsite As SPWeb = oSiteCollection.OpenWeb()
Dim titlesList As SPList = oWebsite.Lists("Holiday_Requests")
Dim query As New SPQuery()
query.Query = "<View><Where><And><FieldRef Name='Author' /><Value Type='Integer'><UserID Type='Integer'/></Value></And><FieldRef Name='Cancelled' /><Value Type='Integer'>0</Value></Where></View> "
' <Eq><FieldRef Name='Cancelled' /><Value Type='Integer'>0</Value></Eq></Where>
'<Eq><FieldRef Name='Author' /><Value Type='Integer'><UserID Type='Integer' /><Eq>
Dim titlesItems As SPListItemCollection = titlesList.GetItems(query)
' showing alternative of using data-binding rather iterating through items..
DropDownList1.DataSource = titlesItems
DropDownList1.DataTextField = "Title"
DropDownList1.DataValueField = "ID"
DropDownList1.DataBind()
End Using
End Using
Ben