Hosting accounts getting suspended

[iso99]

This suddenly happened a few weeks ago. I'm still using the old version Version: 2014-10-17:2014 but regardless of that, it just happened suddenly.

Accounts which shouldn't be suspended (paid invoices) gets suspended on cron run. I tried turning off auto suspend but it didnt work.
I just removed suspension access in WHM, now I'm tracking accounts manually.

Any tips? BTW, any tips involving fixes on DB directly is appreciated, I always find my way around there.