I can report the exact same experience with that combination, only 120 film.
Interesting Chris...
My theory is that, in your case and mine, Brisbane metro water may well be to blame. I have come across a few references (for what they are worth) to XTOL being quite reactive with certain impurities in solution. Brisbane water is pretty hard, and even demineralised/deionised Brisbane water (which I have been using) has probably still got a fair bit of stuff in it.
I have therefore just located a couple of local suppliers of reasonably cheap steam distilled water (in Carole Park - 30c per litre; or in Coopers Plains - 44c per litre) and intend to use this for all my future chemical mixing.
I will test the plan this weekend and see if I can solve my XTOL white spot issue!
Angelo - good luck with the Ilford examination. I look forward to hearing what they report back to you.
Ian


it doesn't matter whether it is the grains themselves moving within a stable gelatine matrix, or the gelatine layer with the grains entrenched in it that is moving, the end result is the same: a (tiny) disturbance of the photographic layer and distribution of the grains.