Upgrade from 3.1.1 to 3.2 breaks time estimates

In upgrading from 3.1.1 (by exporting and importing) my estimates have been erroneously shortened. For example, a task which had an estimate of "4 days" in 3.1.1 now has an estimate of "1 day 8 hours" in 3.2.

I believe this stems from the fact that in Jira 3.1.1 I have set weeks to be 5 days, and days to be 8 hours. It looks like the import has ignored that fact and used 24 hour days to convert 115200 seconds to 32 hours and then to "1 day 8 hours", rather than converting it to "4 days".

If I check "Administration .. Time Tracking", my 3.2 installation is correctly set to 8 hour days.

One other thing that may be relevant is that I am exporting from a Jira 3.1.1 that is using SQL Server, and importing into a Jira 3.2 that is using hsqldb.

I've raised this as a "Blocker" as it is preventing us upgrading to 3.2, but I'll understand if the Atlassian folks downgrade it somewhat. Especially if they can provide me with a workaround.