bRegex does not work with server side processing

Hello,

I don't now if I'm doing anything wrong but I'm trying to use bRegex in server side processing and it is not working. I have a definition like this:
"aoColumns": [
{ "mDataProp": "browser", "bRegex": true},
{ "mDataProp": "status", "bSortable": false },
{ "mDataProp": "version", "sClass": "vShow" }
]

And everything is working expect bRegexp. For bRegex it always sends false:

sEcho=2&iColumns=3&sColumns=&iDisplayStart=0&iDisplayLength=100&mDataProp_0=browser&mDataProp_1=status&mDataProp_2=version&sSearch=&bRegex=false&sSearch_0=firefox&bRegex_0=false&bSearchable_0=true&sSearch_1=&bRegex_1=false&bSearchable_1=true&sSearch_2=&bRegex_2=false&bSearchable_2=true&iSortCol_0=1&sSortDir_0=desc&iSortingCols=1&bSortable_0=true&bSortable_1=false&bSortable_2=true

Is there a bug or I'm doing something wrong?

Thanks,
Cristina