Bleh!!!! more potential problems come out.
However, while AnsiStrings can be misused, I would not necessarily assume your real problem is with AnsiStrings.
The main point of advice in this thread is to program defensively to avoid errors, rather than trying to find the cause of errors after the fact.
Essentially, you are doing exactly the opposite: mashing together sections of code that (you think) worked separately, assuming they will work together, and then struggling to find the causes of errors that occur because you have mashed them together.