TN visa holder on vacation

I have a TN visa for three years . I am currently on vacation. I will be out of United States for more than 30 days , but still employed and on payroll(using up holidays and vacation time), will this pose any issues when I return. Somebody told me, TN holders are not supposed be outside the country for more than 30 days.
Is that true ? Has anybody had any issues earlier ?

Thanks

Roger

Can anybody please reply ? I need to adjust my vacation accordingly !

Thanks

Roger

Can't see why it would be an issue if your I-94 is still valid because you don't surrender it when you leave in TN-1 status, so they don't know when you left.