The dates in dhtmlX Calendar become invisible, on mouse over

Using dhtmlX Calendar in div attached to dhtmlX window as object.

Facing following issues:

1. The background color of current date cell is not there.

2. On mouse over date cell, date disappears and there is no background color

for mouse overed cell.

There are two possible issues
a) you have missed default css file of dhtmlxcalendar
b) you have some custom css rules defined , which affect normal rendering of page ( rules which affect all tags by their name may cause such effect )

The issue can’t be reconstructed locally - it it still occurs for you - please provide any kind of sample where it can be reconstructed.