3 different fusers seems unlikely it is fuser. Though that is often the case that it is. I lookup and see AF3030 is same as Savin 8030 so I ask you, have you replaced the FOAM ROLLER?
Also as mentioned by Allan I often see Reg Roller with something on it, adhesive, corrosion. Also failing Broken plastic holders or springs for the Reg Roller or Relay Roller also cause this. Also maybe plastic bur develop on the plastic paper gates near registration/transport sensor.
Yeah Im also pretty sure its nothing to do with the fuser. My last visit I educated the client on the paper dampness - its stored in their IT room which is cooled at 17 degrees C - and asked them to change the paper as soon as the fault occurs.
I also asked them when they load paper into the trays to move the bottom stuff to the top so the old paper dosnt sit in the bottom of the tray for too long....
I was driving past and called in today and it still creases so im going back on Monday to have another decent look and try out a few of your guys suggestions. In particular the reg roller springs and I noticed the mylar near the reg roller? has a nick in it so I will replace that also along with the foam roller.
So at this stage its definately not the fuser or the paper - ill update as soon as possible, and thanks heaps for the ideas!
It's a long shot, but have you checked that the exhaust fan is working and has sufficient air flow? Also, I came across one of these machines in the filed that had been refurbished and the mylar sheet, under the catch tray that directs the air to the exhaust fan, was missing. This was causing condensation in the optics cavity, but could also possilby cause creasing.
Check the pressure roller springs for the front and rear are attached to same alignment grooves.
If they are different from one another it will give you lob sided pressure / nip band causing the paper to crease intermittently but often.