How can we solve javascript bug when using Lookup field with SharePoint 2010

Have you ever been seeing a javaScript issue like that when click to title of a item from a splist that have lookup field

1. The "Parent Task" is a "Title(linked to item)" lookup field

2. A simple splist item that have a parent task

3. After click on "T2" we see the item information with javascript bug

4. Double click on the javascript at the left bottom we see


5.  Click on "Show details" we see

6. The simple and quick way is come back to "Parent Task" lookup field, choose lookup to "Title" replace for lookup to "Title (linked to item)"

7. Do you worry: if lookup to "Title" only, the value of "Title" lookup have ID of parent item come with? The answer is have. Please see the gantt chat here of TaskMaster

TaskMaster knows parent and child relationship base on ID (number) inside "Parent Task" field

Good luck!
Happy to help you to show the issue. Can email or call me when you want!