Danish Verbal Complements with the modal verb "skulle" 'to have to'

In Danish, as in English, verbal complements may have an infinitival form as its head, as in (1)

(1) It's no fun to have to stay at home.

In Danish, the equivalent to the above example is as in (2)

(2) Det er ikke sjovt at skulle blive hjemme.
it to_be.pres.ind not fun to have_to stay at_home

However, I have observed a non-standard variant which employs a present indicative conjugation on the modal verb resulting in the construction in (3).

(3) Det er ikke sjovt at skal blive hjemme.

This non-standard form seems isolated to this single verb and to some, as of yet, undefined segment of the speech community. A simple Google search revealed that it is not solely a speech phenomenon, i.e. it is also used by people in writing, though by a small group. Thus, only 3 % of cases of at skulle + infinitive employed the present indicative while the other 97 % used the standard infinitive relative clause initiation. This number is bound to be higher in spoken language.
Interesting questions posed by this random observation are:

1. How large is the segment which uses this construction?

2. What is the time depth of this change, and is it winning territory or the contrary?

3. Is there a correlation between this variation and social variables?