Subject Firebird 2.5 - Data committed to database is not found after a while


I have a legacy application written in Delphi XE6 using Firebird 2.5. Since several months ago have noticed that some times table records are not commited to database. I thougt that it was user mistakes with the application but not. They show me evidences that data was typed correctly: For example, one invoice that is fully created and printed, after a while is not found in the database and information is loosed.

I thought that could be some issue related to Sweep interval and Forced writes but the issue persists. It is not constant and I have been unable to reproduce it.

Have checked the database with gfix dont finding errors.

I susspect that it is related  to some kind of data cache that for any unkown reason finally doesn't post changes to disk.

Have anyone had this situation?

Is it posible that it is related to a Windows version?

Sincerely dont know how to work arround this.

Any help will be appreciated.