DMR-EX75 no longer play discs it burnt?

I've had this for about 4 years now and it's been very reliable, apart from the U81 error which I haven't had for a long time now. However, it has recently developed two faults, firstly it will no longer play DVDs that were recorded from the hard drive some months ago and secondly it is a multiregion machine but whereas I seem to recall originally it would "autodetect" an NTSC DVD, now it has to be changed in "Setup". It currently has OS 1.16; has this been changed recently and might it account for the problems?