conjunctions - usages of "in case" together with "should"

Here's a contact number, in case there should be a problem.

( I have seen this version in a dictionary )

My own rephrased sentences:

1. Here's a contact number, just in case there should be a problem.


2. Here's a contact number, in case there is a problem.


3. Here's a contact number, in case should there be a problem.


4. Here's a contact number, should there be a problem just in case.


5. Here's a contact number, should there be a problem in case.



6. Here's a contact number, there should be a problem just in case.

It would be appreciated, if someone could throw some light on the differences between these. I need some more detailed information.

Please feel free to ask me any further question.

Many thanks

Answer

Like @JasonPatterson said, points three to six aren't grammatically correct. In fact point six is almost saying "Here is my phone number, I will make sure there's a problem"!

Points one and two are identical in meaning.