Cubase5 Losing track inserts after closing program.

Hi guys,
I’m pretty new to Cubase, using 5. I’ve recently found a weird issue. The inserts for my tracks, like e.g. HALionOne instruments, or Reverb effects, are lost whenever I reopen the project. I spend hours on perfecting the sound of a track, then every time I quit and reopen, all the inserts are gone. I can save the inserts as presets and load them in again manually, but it’s really tedious.
What’s more: some tracks lose these, while others don’t. I have not found any logical explanation for this. Anyone who experienced the same?

Have you got the latest version? If you can update to the last version of 5 it may solve this.