From our host's tech support:
The ticket canadianactor.com, regarding the bulletin board, has come back from our Tier 2 Support Team. It has been indicated that we can advise you nothing as long as you are using test files to store data. Our only suggestion is to use a database to avoid this slowness. The ticket is now closed.
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I presume there is nothing we can ask our host to do, nothing that they have not thought of that they might be able to implement? If that's the case, we will have to look at another Board or another host. It is, sadly, no longer functional to keep running this board the way it is going.
