Sharepoint SPQuery on SPView problem

I have created a CAML query to get some particular items on a list, that contains OR:

 <Or>
    <Eq><FieldRef Name='Title'/><Value Type='Text'>tileA</Value></Eq>
    <Eq><FieldRef Name='Title'/><Value Type='Text'>titleB</Value></Eq>
 </Or>

Now the query works fine if I pass it to list.GetItems() metod, but it doesn't work when I use it like that:

SPContext.Current.List.DefaultView.Query = myStringQuery;
SPContext.Current.List.DefaultView.Update();

I place the code in a webpart (Page_Load()), that is added to the list, the code executes, but the view remains unfiltered. Anyone knows what might be the reason for that?

Two things:

First, make sure your CAML is wrapped in a Where element:

<Where>
    <Or>
        <Eq><FieldRef Name='Title'/><Value Type='Text'>tileA</Value></Eq>
        <Eq><FieldRef Name='Title'/><Value Type='Text'>titleB</Value></Eq>
    </Or>
</Where>

Second, rearrange your code like this:

SPView view = SPContext.Current.List.DefaultView;
view.Query = myStringQuery;
view.Update();

I know the code blocks looks the same, but neither SPContext nor DefaultView use private fields. For example, here is the implementation of DefaultView:

internal SPView DefaultView
{
  get
  {
    if (this.m_iDefaultViewIndex == -1)
      return (SPView) null;
    else
      return this[this.m_iDefaultViewIndex];
  }
}

public SPView this[int iIndex]
{
  get
  {
    if (iIndex < 0 || iIndex >= this.Count)
      throw new ArgumentOutOfRangeException();
    else
      return new SPView(this, this.m_arrViewSchema, iIndex);
  }
}

So with:

SPContext.Current.List.DefaultView.Query = myStringQuery;
SPContext.Current.List.DefaultView.Update();

The first line sets the Query property of an instance of DefaultView while the second line calls Update on a new instance of the DefaultView.