In free-play in the download version you can get Playcheck data for the current session. I think it disappears once you disconnect.
Not sure if the same applies for the Flash version, which I think is what Loganberry was playing.
Microgaming P4F stores the data locally. I found this out by experiment.
You need 2 computers for this, and install the same MG download casino on each. I used Golden Reef.
On computer 1, deposit and play a slot such as "Ho Ho Ho" until you have the free spins. Disconnect. According to MG rules, the free spins should stay until you reconnect. Reconnect, and check. The free spins will be there. Also make a note of your balance.
Now, over to computer 2, log in to the same P4F account, and take note, you will find NO free spins and NO balance preserved between computers.
Go back to computer 1, and you will have your free spins and balance as they were when you played on computer one.
The ONLY thing P4F uses the server for is generating the results of each game, this can be shown by disconnecting the internet cable and spinning the reels, they just spin, so are not using the local RNG, but the one on the server.
It is possible that the problem is a display bug, and not a "real" non-payment of a winline. This can be checked with Playcheck, which IS stored for P4F on download Golden Reef.
I will see if I can reproduce this "line 12" problem there, as if I can it points to the possibility of an MG bug, rather than a corrupt installation on one PC.
There IS a display bug on Thunderstruck, and it frequently locks on "-1 spins left" with the first two reels stopped and the other three spinning forever. This is linked to the autoplay bug that means the selection of "quickspin" has no effect at first. I have found this display bug is triggered when a spin during free spins hits, or exceeds, the "stop when balance exceeds...." options in autoplay. The slot does a "double jump" through 2 results, and this causes the display to lock, or to suddenly start to run the spins ignoring the quickspin option.
Microgaming don't give a rat's a*** about this, it has been reported for two years, and has never been in the frame for being fixed in the upgrades.
They give MANY MANY rat's a***s when problems affect the CASINO, such as where a bug allows players to exploit a flaw in the code in some way.
This was the case when EZBonus first came out, there was an exploitable flaw that was fixed within a few weeks, not that players were complaining about it. When they plugged this loophole, they created an error that worked in favour of the casino. (The one where you deposit into a zero balance, and suddenly the WR returns from the long lost previous bonus as you see your fresh deposit turn partly to bonus chips). Have they fixed this, NO!! It has been complained about on this forum, and one complaint went to eCogra, but all they do is make corrections on an individual basis provided players notice, and jump through the hoops of convincing CS there IS an error (I just don't bother, too much trouble - but I know the bug exists, and know how to minimise it's effects by making a small deppsit to "clear the cobwebs" before making further deposits - even 10 chips from comps will do the trick, it will change to bonus money, but the bug won't then affect the next deposit unless you are REALLY unlucky).