Sitecore field value being truncated at 255 characters?

Question

I am encountering an issue where the value of string -- stored in a Single-Line Text field -- is returned as being truncated to the first 255 characters. When I look in the Content Editor, I see the excess characters. If I query the database using Sitecore Rocks I see the extra characters.

Is it possible this is being caused by GlassMapper?

In the code samples below, it is the LinkText that is being truncated.

My models...

using Glass.Mapper.Sc.Configuration.Attributes;
using Glass.Mapper.Sc.Fields;
using MySite.Extensions;
using MySite.Models.Base;
using Sitecore.Data.Items;
using System;

namespace MySite.Models.Items
{
    [SitecoreType]
  public class LinkItem : ISitecoreBase, ILinkItemBase
  {
    // ISitecoreBase
    public virtual Guid Id { get; set; }
    public virtual string Path { get; set; }
    public virtual Item InnerItem { get; set; }

    // ILinkItemBase
    public virtual string LinkText { get; set; }
    public virtual Link LinkTarget { get; set; }

    /// <summary>
    /// Does the link have neccessary content?
    /// </summary>
    /// <returns></returns>
    public bool IsValid()
    {
      return this.LinkText.HasValue();
    }
  }
}

---

using Glass.Mapper.Sc.Configuration.Attributes;
using Glass.Mapper.Sc.Fields;
using MySite.Extensions;

namespace MySite.Models.Base
{
    [SitecoreType(TemplateId = Constants.TemplateIds.LINK_ITEM_BASE)]
  public interface ILinkItemBase
  {
    [SitecoreField(Constants.LinkItemBase.LINK_TEXT)]
    string LinkText { get; }

    [SitecoreField(Constants.LinkItemBase.LINK_TARGET)]
    Link LinkTarget { get; }
  }
}

---

The logic snippet... by line 3 of GetLinkItems, the LinkText of the items in this.LinkItems is already showing up as truncated.

public virtual IEnumerable<LinkItem> LinkItems { get; set; }

public ICollection<LinkItem> GetLinkItems()
    {
      ICollection<LinkItem> linkItemCollection = new List<LinkItem>();

      if (this.LinkItems.HasItems())
      {
        foreach (LinkItem LinkItem in this.LinkItems)
        {
          if (LinkItem.IsValid())
          {
            linkItemCollection.Add(LinkItem);
          }
        }
      }

      return linkItemCollection;
    }