Code fails when ran within Userform, but works when ran from Macro button on worksheet.

I am using the following code to create a PDF of some search results and then email them:

Please Login or Register  to view this content.

On the Search Page the user clicks Email Search and a UserForm is opened, allowing the user to enter the email settings (Addresses, Subject, Body etc). When the user selects the Send Email button the settings are saved on the EmailSettings sheet, and the code above is then executed. However Im getting the following error:
Run time error 1004
Method 'Close' of object '_Workbook' failed.

If I run the email code by itself, and enter the data into the EmailSettings sheet manually it works fine, it only fails when ran from the UserForm.

I have attached my workbook.

Is this code to replace the following code:

Please Login or Register  to view this content.

I tried doing that but again it works fine when I run it in VB, but when I run it from the macro in the UserForm I get the same error as before:

Run time error 1004
Method 'Close' of object '_Workbook' failed.

How would that work exactly, I'm not sure I'm following you?

Makes sense, I dont know why I didn't think of that.
However at first I was getting the same 1004 run time error, and it failed to close the temporary workbook and to send the email.
So I added a line to close the UserForm before running the email code and it worked fine. How can I get it to work without having to close the Userform?
I tried just having it re open the user form when the email code completes, but since it takes a few seconds for that code to run its a little impractical.