public class MyHomePage
{
    IWebDriver driver = null;

    [FindsBy(How = How.LinkText, Using = "Home"), CacheLookup]
    public IWebElement lnkHomeTab { get; set; }

    [FindsBy(How = How.TagName, Using = "Title"), CacheLookup]
    public IWebElement pageTitle { get; set; }

    public MyHomePage(IWebDriver driver)
    {
        this.driver = driver;
        PageFactory.InitElements(driver, this);
    }
}

public class MyHomePage
{
    IWebDriver driver = null;

    [FindsBy(How = How.LinkText, Using = "Home"), CacheLookup]
    public IWebElement lnkHomeTab { get; set; }

    [FindsBy(How = How.TagName, Using = "Title"), CacheLookup]
    public IWebDriver pageTitle { get; set; }  <-- The issue is in this line.

    public MyHomePage(IWebDriver driver)
    {
        this.driver = driver;
        PageFactory.InitElements(driver, this);
    }
}