Such behavior is considered to be a software issue which is fixed since PBAS version 4.5.2:
PBAS-29271 - Inactive PPA DNS records are added into PBAS upon force DNS sync
Upgrade PBA-S to the latest version.
Hotfix for PBA-S 4.5.1 CentOS5, 32-bit
The hotfix is attached. Download the file to PBA-S node and install it using the following commands:
# rpm -Uhv hspc-pa-4.5.1-19.swsoft.i386.rpm # hspc-upgrade-manager --finish