Layer Null issue

Hi,

I have downloaded Openlayer version 2.13.1 for using Open Street Map. I was getting following errors in different browsers:

1) In IE after zooming in for one level I was getting this error "Unable to get property 'maxExtent' of undefined or null reference"
2) In FF after zooming in for one level I was getting this error "TypeError: this.layer is null"

And after that zooming in had stopped working it and it was not zooming in properly.

Then I downloaded Openlayer Version 2.12 and this issue was gone.

Kindly check this in 2.13.1 and provide your feedback.

Thanks,
Harshil Shukla