Unfortunately - no.
I had some spare time today to try again a fresh upgrade using the latest version of SMW 1.5.6 from Feb, 24th. Regardless of the value of $smwgAutoRefreshSubject , I end up with a time out when I try to save a page (with or without using forms).
I even tried to upgrade first to 1.5.5 and then to 1.5.6 - but I got the same time out issue.
By the way, there is a typo in the SMWAdmin update script : RAP model exiists (instead of 'exist').
Did putting $smwgAutoRefreshSubject = false; solve your issue?
Jeroen De Dauw
Don't panic. Don't be evil.