Release 0.69/0.70 contained major architectural modifications enabling IDN support and the enrichment of the text, mailbox and domainname rdata fields. The new architecture also addressed some less visible improvements on the internal workings of Net::DNS (providing clearer separation of concerns and better protected module-interfaces.)
We have done our utmost best to introduce architectural changes as gradually and incrementally as possible in the hope to detect and resolve issues quickly. Nonetheless there is a point were all the pieces have to come together. For our architectural refactoring with Net::DNS this was in the previous version 0.69/0.70.
As a result, we have had a bigger number of critical bugs then normally after release. Release 0.71 has those resolved.
One issue that stands out is SpamAssassins update mechanism for spam-rule datasets to silently fail with Net::DNS 0.69/0.70. Spamassassin expected the rdatastr method of TXT rrs to return unconditionally quoted strings. Release 0.69/0.70 returned those conditionally in accordance with RFC 1035 section 5.1.
To resolve we agreed with SpamAssassin developers that Net::DNS 0.71 will have a temporary workaround that returns unconditionally quoted rdata fields again. This workaround will be reverted after SpamAssassin has released a version with the problem resolved.
It is already fixed in the SpamAssassin repository.
For a complete list of changes and bugfixes see the CHANGES file.