I restored an old backup and my discussion threads/SMS messages disappeared - only old ones are left.

How can I restore the previous situation, or how can i detect my missed data?

I cannot use any code. In case of laptop I use MS system restore point options or Recuva application.

Please help!

The backup overwrote your previous SMS message database, so I'd guess it's gone for good. Unless you took a backup before restoring?

Why can't you use any 'code'?

So they are lost?

The most recent ones (last 25 or so) may still be recorded in your SIM, but there are no SIM tools for the N900. If you can access another/older phone (like a 6230) you may be able to get that phone to read the last couple dozen SMS from the SIM. Your service provider may also be able to provide a listing of them as well (or on their website).

When you restore from a backup, you're telling the system to delete any changes done since the backup was made. That includes SMS. Why is that confusing or unexpected?

I would suggest you use a backup logging tool (like glogger, or OVI Suite) to backup your SMS if they are that important to you.

Thats how back ups are supposed to work. In order to restore a back up it is necessary to remove any "harmful" changes.

Thank you, unfortunately they were not on the cards - as seem to case with my other phone/sim card.

I found all intentionally deleted files with Recuva and Diskdigger, but because these lost sms messages are not deleted, they could not find them.

In fact the lost data is still on the disk of my N900. Problem is how to identify it.