The mobile subdomain runs under PHP 5.4 but the main domain runs under PHP 5.6. I never realized that they run under different PHP-versions.
That's curious to know, thanks... I suppose, the newest mobile version will not require a standalone sub-domain anymore, so the problems will be the same for both versions in the future :) However I'm still wondering how PHP could be involved in that... file caching or something... The functions we use for this flat-files PM module, are absolutely native and very transparent, nothing about specific classes and libraries... that's actually would be the proper solution to investigate: why
PHP 5.6 handles the files differently other than 5.4.
But if you're happy so far with an existing solution, that's fine for me.
I think I should upgrade to your latest PM service addon.
You could get the latest version from your Customers area, and I suppose, this is the right time to get it for your older miniBB version, since the newer PM module for miniBB 3.3 released this summer, will have even more incompatibilities regarding the older miniBB versions. However, like I wrote above, most functions in the current PM module were not about messages saving principles, but mostly about compatibility issues with the newest miniBB versions, and there were also no security patches
. I suppose, because of that, you could still stay with your older add-on so far.