Good spot, thanks: not all my feeds are being updated by the cron job. I'm not sure what determines which are and which aren't.

A manual update by loading "www.mysite..../selfoss/update" seems to work okay. I've taken to using this rather than the cron job I had previously in order to cut down on error messages/logs.

I haven't tried the git version yet - from a quick scan of the changelogs I couldn't explicitly see anything to suggest this issue had been addressed.