can't paste images in richtextbox

[baiumbg]

I'm having trouble with a bit of code here. What I'm trying to do is paste multiple images(generated from a helper function) into a RichTextBox. Here's my code:

string tempText = "For the arithmetic progression $a_1, a_2, a_3, ... a_9$ it's known that $a_2 + a_8 = 8$. The sum $a_1 + a_2 + a_4 + a_5 + a_6 + a_8 + a_9$ is equal to:\nA) 14;\tB) 16;\tC) 36;\tD) 32.";
            for (int i = 0, lastOcc = 0, numDoll = 0; i < tempText.Length; i++)
            {
                if (tempText[i] == '$')
                {
                    numDoll++;
                    if (numDoll % 2 == 1)
                    {
                        problemText.Text += tempText.Substring(lastOcc, i - lastOcc);
                    }
                    else
                    {
                        string equation = tempText.Substring(lastOcc, i - lastOcc);
                        MessageBox.Show(equation);
                        try
                        {
                            CreateGifFromEq(equation, "temp.gif");
                            Bitmap eq = new Bitmap("temp.gif");
                            //eq.Dispose();
                            Clipboard.SetDataObject(eq);
                            DataFormats.Format f = DataFormats.GetFormat(DataFormats.Bitmap);
                            //problemText.ReadOnly = false;
                            this.problemText.Paste(f);
                            eq.Dispose();
                            //problemText.ReadOnly = true;
                        }
                        catch (Exception ex)
                        {
                            MessageBox.Show(ex.ToString());
                        }
                    }
                    lastOcc = i + 1;
                }
            }
            problemText.Text += tempText.Substring(tempText.LastIndexOf('$') + 1, tempText.Length - tempText.LastIndexOf('$') - 1);

The images generate without any problem, and the text seperates properly. Only problem I'm seeing is pasting.

The following on a seperate blank project, however, works without any problems:

                    try
                    {
                        CreateGifFromEq("a_1, a_2, a_3, ... a_9", "temp.gif");
                        Bitmap eq = new Bitmap("temp.gif");
                        Clipboard.SetDataObject(eq);
                        DataFormats.Format f = DataFormats.GetFormat(DataFormats.Bitmap);
                        this.problemText.Paste(f);
                        eq.Dispose();
                    }
                    catch (Exception ex)
                    {
                        MessageBox.Show(ex.ToString());
                    }

What do I seem to be missing?

P.S. I CAN paste images manually.