Yup, typical timing issue... and your subject actually explains it all. The automation attempts to run at "full speed" so, when it goes to perform an action, it attempts to do so as soon as possible without being "smart" about the application. So, your bug might actually be due to TestComplete attempting to do something against your AUT before it's ready to...
There is an option in Tools -> Current Project Properties -> Playback called "Auto-Wait Timeout". This is how long TestComplete will wait for an object before it says that it cannot find the object... increasing this value MAY help your situation.
However, a better way is that, in your automation, build in specific checks to "wait" for the application to get to a particular state before the automation moves on. This is using methods like WaitWindow, WaitAliasChild, WaitChild, etc. These will tell TC to wait up to an indicated time for the designated object to resolve. If it resolves before that time, the method will return the object. If it doesn't, the method will return a "stub" object with the Exists property set to "false". Add checks in your code to use these "Wait" methods to check to see if something exists before your automation moves forward.
You can also use "WaitProperty" to wait for the property of an object to change to a particular value. WaitProperty operates on the same principle in that it will wait a maximum time. If it returns before that time, WaitProperty returns "true". If not, it returns "false". So you can use this also to build in custom "wait" methodology.
To second that, if you could provide more information about what is actually happening vs what you expect to happen, your mappings / code snippets or screenshots of your KWT someone around here can probably point you in a good direction to start figuring out what exactly is the issue in your situation.
