Warning - I don't suggest you do this unless you feel comfortable editing files. I suggest you make a backup copy of your workbook.
If you use a texteditor like NotePad++, open the workbook file in the editor. This file is XML based.
Look for the worksheet name that is freezing on you.
Remove the text starting with this tag to the first closing </worksheet> tag.
Please only do this on a copy of your workbook in the event you make a mistake!
This worked for me.
Thanks for posting your solution!
Yes, the .twb file is just XML and can be viewed in any text editor. I like NotePad++ too If you take the .twbx file and change the file extension to .zip you can then unzip the file and you will get at least two files out of it, the .tde and .twb The .tde file(s) will be located in subfolders (..Data/Extract).