Situation:
actual tested with 7.3.4 and dev (incl. date), drupal 7.22
activated cach in calender view for all, incl. Block

Problem:
Using a calendar block in a region, ther the prev and next Links are not working. No change of the month is happening.

A Link Example for the Block View, actual staying on August:
prev: http://example.com/webkalender/month/2013-08?mini=2013-07
no change happens

In the Month View the Link of the prev Link si like this
http://example.com/webkalender/month/2013-09

The Problem only occurs when caching ist active set.
By the way ical is not working too while caching. But caching is neccessary because the performance is to bad.