Knot 1.5.2 crashing

Yesterday I updated 2 of our servers to Knot 1.5.2, but on one of them, knotd keeps crashing with an error like:

Sep 9 07:10:17 ns2 kernel: knotd[28174]: segfault at 0 ip 0000000000431b39 sp 00007fd7ddbd85c0 error 4 in knotd[400000+50000]

The last line in the log when this happens is:

2014-09-09T07:29:03 notice: [com.vn] IXFR, incoming, 193.0.0.198@53: fallback to AXFR

I could try and delete the com.vn zone file and the journal files and start again, but before I do that, you may want to discover the bug, if there is one, and fix it.

Please let me know how I can help. Keep in mind that I cannot keep this server offline for too long, so I will either have to fallback to 1.5.1 with the patch for CVE-2014-0486, or find a fix for this.