Ldw-451 reading with mechanical vibration after fw flashing

Hi, all
after two years of burning without a failure, i have flashed the ldw-451s with 832 vsom pat.cross.fl… now this dvd burner at the beginnig of reading a dvd-rom for about four minutes makes a strong sound of mechanical vibration while reading without errors. after the reading is normal.
the question is the following:
the dvd burner is out of order or this problem is due to the updating?

I use a 451@832 for more then 2 years now (thnx Code) without problems and flash it back and forth quite often.
Could coincedence and it’s just on it’s last legs.

the problem (if this is a problem) appears only with one dvd-rom media. the 451 has a greater vibration, but I thing this is normal, within its specification. thanks, Code. now I am using the 451.stock.

Have the same thing with “The Matrix”. It’s hole is not exactly in the centre.