bind generating db-* files

[mark evans]

I am running BIND 9.4.1-P1.  My name server is generating files with names
similar in formate to "db-Z9MkkEBr". At first i thought it was because a old
script was running and older version of bind.  But the files are still being
generated after that issue was addressed. A named.core file is not being
generated.  I'm not seeing anything odd in the syslogs. Anyone have any tips
for me on how to figure out what is going on with these files?
Thanks
Mark