Exposed link filter loses text on ajax table sort.

I have an issue with the exposed link filter having it's text revert to '1' when I sort the table rows with views ajax sort. However, this only happens on one table out of 3.

This is a page which doesn't have any problems, you can sort the table and the exposed filter text stays as the year:

http://scubascuba.jiminy.co.nz/maldives/liveaboards/trip-reports?field_y...

Now on this page try to sort the table by any field and you still see the filter text becomes '1':

http://scubascuba.jiminy.co.nz/maldives/liveaboards/schedules

The only difference between the filters is that the ones which do not break have are filters by relationship. The one which does break doesn't have any relationship on the filter. Apart from that I cannot see any difference between them, but am happy to provide any further info of course ;)

Here is the third page which also doesn't have an issue: http://scubascuba.jiminy.co.nz/maldives/liveaboards/guest-comments?field...