How to redirect exposed view filter form submission?
Thanks for the additional info, it adds a lot of light to the issue. I am not exactly sure what is going on but maybe an explanation of what drupal does might give you an "A-ha! That's where I entered some info wrong" moment:

In the code, drupal/views/etc uses form redirects:

$form_state['redirect']= VARIABLE OR CODE TO SET IT TO A PATH


that is obviously mangling the redirect into:

http://domain/?date_start=12


What is interesting here is it is setting that url to the date_start value instead of adding that to the url:

http://domain/myselfcare/communications?order=destination&amp;sort=asc&amp;date_start=12


So here, instead of adding ?date_start=12 to the end of

http://domain/myselfcare/communications?order=destination&amp;sort=asc


it's replacing it all (additional vars get the ?= changed to an &amp;=)

So, I'd look at how you are defining date_start in your view forms and see if anything odd pops up there.  That or in your theme code setting the redirect to that directly.