first of all, when you try to verify your disk with disk utility, do not press anything! Leave it until it finished its work. That error you mentioned, I saw this too when I cancelled the operation before it was completed.
Have you tried reinstalling toast?
Have you updated prebindings?
If all else fails, download the 10.4.3 Combo update and install it over your existing 10.4.3 update. This will probably fix your problem, as it has for me, when I did the update from 10.4.1 to 10.4.2. This also happens to a lot of people. Many have problem with the delta updates. So, they download aftewards the combo update and they are just fine.
NOTE: Do repair permissions after the update. You will see that it will find a lot of permissions that need fixing.
Let us know how it goes after these... I stronlgy recommend the combo update.