This is quite befuddling. Possible answers:
- Does not support earlier versions of IE (we don't use IE with Moodle on my campus)
- Might want to only extract the laegrader folder and leave your other grade folders intact. There is so much reliance on libraries outside of the gradebook tree in the gradebook reports that we have isolated the code in the laegrader to be functional across multiple versions (same version works for 2.2 as 2.3)
- If none of this stuff helps you (the above steps are the easiest) turn debugging up to developer level and see what gets reported
Feel free to email me directly with questions.