Yes, but you've given us insufficient info to be sure. However, that's one of two (obvious ... and who knows how many non-obvious) possibilities:

1. "some error in the code...."
2. using == instead of eq for a non-numeric comparison

If your check (via Mark I eyeball, debug, print statements, etc) shows 2 is NOT the issue, then yes, posting some code would allow us to be more helpful. But, before posting, reduce your code to a minimal, runable example. Then be sure to also post at least a (small) sample of the data (perhaps as comma-delimited or tab-separated text).