Endpoint Protection

We are software developers and we are producing a telephone call billing system, which has "long-running" programs, e.g. collecting data on-line by serial ports. We load the collected data into Btrieve 6.15 (very old version) database.
We have sold our product more than 5000 times, but never experienced the following:
One of our customer is using the Symantec Endpoint Protection Version 11.0.4014.26 and if this product is working, we get Btrieve error messages very often (at least twice in a month). If the product is switched off, we get no errors (we have tested a 3 month period). The error message is: "The application encountered an I/O error" the database file is damaged and must be recreated.
The operating system is Windows XP.

What can we do? What is the reason?
We tried to exclude our directories from the protection, but there was no change.

Please help if you have heard some similar!

 Well if it is a problem then it will be either Application and Device Control or Tamper Protection causing the issue.
However can you give more details on this problem.

1.What all features are installed on these  machines ( Antivirus n Antispyware, Proactive Threat Protection and Network Threat Protection )

2.When exactly do you get is message. Is it random or on executing certain command or application ?

3.Symantec has recently released its latest version of software 11.0.5002.xx can you try installing that.
Download it from https://fileconnect.symantec.com

Could the program be doing some direct memory or disk access that might be considered "virus-like?"

Sorry because of the long delay, but I could not check the forum.
What does it mean "virus-like"? My software is written in Delphi 5.0 and I use the memory management tools given by the Delphi only (nothing extra). I hope that this is correct. It works well at all other customers. I use the btrieve but a know nothing about its inner processes (I am a user only).

Can you update us after following the suggestions i mentioned above.