Thanks for your reply.
Previously removed everything from the dialog box(internal grabber) because wasn't using tvheadend built in cron. Nightly from the OS cron I do a stop, backup, start of tvheadend. Starting tvheadend triggers the tv_grab_file . Apparently when you have EPG modules enabled and NO cron entry it does this. Added this to tvheaded dialog box -
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Fixes the problem
Below are the OS cron jobs that setup tv_grab_file and do the backup
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hts ( zap2xml.pl -q -D;category-filter.pl /home/hts/.xmltv/xmltv.default.xml > /home/hts/.xmltv/xmltv.xml )
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* root ( /home/hts/backup.sh )