SVN checkout slow after upgrading from 5.1.0 to 5.6.2

SVN checkout is extremely slow from Bamboo after upgrading from 5.1.0 to 5.6.2.

Manually performing an SVN checkout on the same server takes about 5 minutes to check out 1.3GB of code but Bamboo is taking a long time to perform the same checkout:

• Checkout time using svnkit 1.7.13: 4:20
• Checkout time using svnkit 1.8.6: 8:35
• Checkout time using native client: 1:45
• Checkout time using Bamboo: 55:42

The SVN server is CollabNet Subversion 1.7.9
The SVN client installed on the build server is CollabNet 1.7.11

This has proved to be a bug in the third-party SVNKit library: http://issues.tmatesoft.com/issue/SVNKIT-553

Some tweaks that might help:

• Using SVN Export
• Setting the working copy format to 1.6 (Navigate to: Administration > Repository settings > Subversion (tab))