I reported an issue with the middle mouse 'Pan' button sticking intermittently with Draftsight 2020SP1 and was told to downgrade to SP0 until SP2 was released. It seems this was affecting a number of other users too and i haven't had the issue with DS over many years. 

I tried this but SP0 just crashed so i had to go back to 2020SP1.

I have now installed DS 2020SP2 and I still have the same issue, which is driving me crazy.

What can i do to resolve the problem?