There is a thread called "V1.009 is RELEASED" near the top of Product Chat. At the time of this writing there are just under 300 posts in that thread(long, but a lot of info in there). However, that thread is where most bug reports on v1.009 are being posted due to the request by RickV in the first post, and many are being resolved. The "disappearing entities" is commented on quite a few times in that thread. It has not been resolved, and probably won't be until sometime after TGC gets back to working on Reloaded, which will be some time after the 1st. As for memory, 4GB is now the limit apparently, so that is not the cause.
MAME Cab PC: i7 4770@3.4Ghz (passmark 9945), 12GB RAM, Win 8.1/64, GeForce GTX645 (passmark 1898); Shiny new laptop: i7 4800MQ@2.7Ghz (passmark 8586), 16GB RAM, Win 8.1/64, GeForce GTX870M (passmark 3598); Old laptop: i5@2.3Ghz, 8GB RAM, Win 7/64, Intel 3000 graphics