I have sortable ordered list with a few items. Each item in that list can be deleted and/or moved and I can dynamically add more new items. All works fine as long as I do not add a new item and delete one of the existing one.

Example: I run the code and get a list

1. ABC
2. CDE
3. EFG
4. GHI
5. IJK

I delete "3.", so item "4." moves up and is now "3." on that list, while "5." ist now no "4." So far so good.

If I add a new item it will be added at the end of the list as no "6.", "7." and so on.

But as soon as I delete or add any item I am running into problems with the numbering of the list items. I suddently have a list looking like that

e.g.
1. ABC   
3. EFG 
3. GHI 
4. IJK

The numbering is no longer correct. What can I do to prevent this from happening!?
This problem seems to occur only in INTERNET EXPLORER....!!

--> jsFiddle Demo: http://tinyurl.com/kty73o6

Thanks for any advice!