Problems with if clause

Calc, Version: 4.3.7.2, language=English, Mac OSX 10.9.5.
When I enter
=IF(AND(B4<B5;B5<B6);“x”;A5)
semicolons are converted into commas
The formula sometimes evaluates to TRUE or FALSE, but column A contains only numbers
Any hint?

Do you have an actual example where the formula does not behave as you expected?

Semicolons changing to commas depends on your settings of parameter (function) separator under Tools->Options->Calc->Formula.