Dear Martin,
Yes I have installed the 1.4 development version earlier. I again made a fresh installation of moodle1.3.4 but with the earlier moodle database and as per your instruction I deleted those 3 records with version no. starting with 2005. Still the problem is persisting.
Now it shows
Version mismatch: block calendar_upcoming can't downgrade 2004052600 -> 2004052400 !
Now the version for calendar_upcoming is 2004052600 only.
Please let me know, how to proceed.