Script Function is not working with driver script, but Function working fine on debug mode. what is the problem

Hi,

In QTP , SCENARIO: when i run driver script , 5 script is working fine and six script half working fine but one function is not working through driver script. when i debug this script , function and all Lib function is working fine . even i run normal mode then getting error , Debug mode is working fine.

Pls tell me what is the problem in this script or lib files

Regards

Vimal