I'm using this plugin (version 1.2.9.) in a project and it works perfectly, but I found a problem when grouping row contains complex HTML.

The grouping table column contain some text and links (it can seems weird but there's an explanation for this need!). Suddenly the table became very slow and I found that the problem is the automatically generated css class that not only contains cell text, but the whole sanitized HTML.

I fixed the problem changing the code of the _fnGetCleanedGroup function:

...
sGroup = $.trim($('<div>' + sGroup + '</div>').text());
return sGroup.toLowerCase().replace(/[^a-zA-Z0-9\u0080-\uFFFF]+/g, "-");

I'm not sure if this fix can behave side effects, but I think that something can be done for fixing this kind of issues.

Apart this problem: great plugin!

Same issue here! I think there should be a setting for this to swith css-class-generation on/off.