After updating from 10.5.7 to 10.5.8 evrything went fine except, as I later found out, no sound and no time machine. The time machine started from a new instance. The old file (with 10.5.7) still on the dick but apparently inaccessible to time machine.
Use GA-EP45. Any hints how to recover?

Have you been able to resolve these two issues? If not, the way I got the sound to work was I copied the HDAEnabler.kext and AppleHDA from your Time Machine backup. As for the Time Machine, what's the exact error message you're getting?