xf:alert not working on fr:number

When defining restriction (e.g. required) on fr:number component with alert message there is no tooltip presented while moving cursor over asterisk.

Following modification in xforms.js for mouseover event handler did the job:
was:
if (! ($(control).is('.xforms-control, .xforms-group')))

is:
if (! ($(control).is('.xforms-control, .xforms-group, .xbl-component')))