When Ubercart detects that you have enabled page caching on your site, either in normal or aggressive mode, it displays a cachable version of the cart block that only includes static HTML. This change came into effect for all versions after Ubercart 2.0-beta3. Previously, if page caching was enabled on a site, anonymous users would see "ghost" items in the cart from any anonymous users who browsed the site before them. Ubercart was also unnecessarily dumping the page cache in various places pertaining to the shopping cart, causing Ubercart sites to lose practically all of the benefit of page caching.
Im stuck in D6 for now and I tried to use the Ajax Blocks module to see if it might help tie me over until a solution has reached. The advice about that came from this thread
Sadly, for me, that did not fix the problem. I still get the "click here to view shopping cart" prompt. Its an annoyance really but not enough that I want to risk trying to upgrade to D7 at this time (too many other key modules I use are still working the bugs in D7 or in alpha status on 7.x releases). Any ideas?