When Display options - Display posts from previous days in UCP is set to a value other than "All posts" and a topic is viewed that shows only 1 or no posts because of the filtering by days, it is not possible to modify the filter to show posts of a longer period or to show "All posts" in prosilver. (subsilver works good)
Reason is that in viewtopic_body.html the following condition is used:
<!-- IF S_NUM_POSTS > 1 or PREVIOUS_PAGE -->
I think the condition is not required, but have not tested it. Previous and next page buttons are allready conditional and the "select sort" part should be shown always (except for bots).