Looks like your backup battery is dead. In that case, you loose all the presets each time you switch off the synthesizer.
And the EX800 has no factory reset. The only way to reset it is to load the factory tape or the vstizer factory bank. So if your battery is dead, it will not go automatically to factory.
I think the vstizer can help you, but you will need to reloead the bank each time you start the synthesizer. And I would recommend you to change the battery asap, I almost killed my EX800 because the battery was leaking inside.
Anyway, the best thing to know if the plugin can help you is to contact the programmer of the vstizer at KISSBOX. He knows the EX800 very well and will be able to help you.
sorry for the delay to answer, but I just noticed that the discussion flag was not active (I was not informed when somebody was discussing about the VSTizer EX800)
We decided to stop the sales of the MIDI version, and only the RTP-MIDI version is available now. We had many customers reporting bad behavior of their MIDI interface and/or sequencer, which were not able to deal properly with the big SYSEX packets produced by the EX800.
The problem is that we could not do anything within the plugin to solve problems related to the VST host and/or MIDI drivers. That's why only the RTP-MIDI version is now available.