The requirement for using SVN 1.7 compatible connectors is using the Subversive 1.0.0/1.1.0 versions. They're supporting Eclipse starting from 3.6 version. Support of older Eclipse versions was removed. More information about requirements you can find here: http://www.eclipse.org/subversive/latest-releases.php
Also please take note that we're supporting only the latest 3 Eclipse Platform versions. So, though it may still actually work in older releases - officially it is not.
So you may try installing recent plug-ni versions, but there is no guarantee they'll work in older Eclipse releases.