>hi Naomi
>I've tried that and all obvious things but don't see any bug in the code. that's why I want to trap program that's updating. I added a timer that checks the data on interval but question is how do you find out what program just replaced some text ?

Assuming that updating changes the modification date of the table you can bind to Windows events and monitor changes on the file. There is a sample in solution how to hook to Windows events.