Support Request: license disapeared

Reproduction

Hi,

After upgrading to Sitekiosk 7 (license was from this year), we have series of problems.
Everything seems to be ok, but after couple hours sitekiosk shows message (Sitekiosk unregistered).
When I've enter registry there's key "signature" but no "licensee". After reinsterting keys (either from registry or reg wizard in sitekiosk) it works for about 5 hours and notice appears again.

After deleting registry entries and making new registration from program, I've noticed that sitekiosk 6 created entries "signature" and "licensee". Sitekiosk 7 creates "Signature" and "Licensee". Does it make any difference to program?

Codes were also copied and typed manually, error still appeared. In couple machines after insterting it about 10 times in 10 days, finally everything works. Pityfully new machines have same error.

Can You help with this?
We've installed couple hundred machines with sitekiosk 6 and there were never problem with license.