VirtueMart Category Module - not all categories opening

[jillymot]

I have been looking through the forums for the past hour trying to figure out what the problem is here.

I am using Joomla 2.5.7 and just updated to VirtueMart 2.0.12b from 2.0.8 but this error was occurring before updating.

The site I am developing can be viewed at the following location:
[link removed]

When first looking at the site tonight, I could not view the following categories from the VIEW CATEGORIES menu on the left:
- Clothing
- Books
- Drinkware

and was getting the error in Firefox "The connection was reset.   The connection to the server was reset while the page was loading" when trying to open each item.

Somehow Clothing and Drinkware seem to have resolved themselves.  This seemed to happen when I changed the https to an http for the URL for Drinkware and the page appeared and then appeared again using https URL after clicking on the menu item again.  Immediately after the Clothing URL also worked again after clicking the menu item.

However the Books category is still not opening.

My client wants to go live with the site over the weekend, but I'm at a loss as to how to fix this. 

Any help would be greatly appreciated.

[UPDATE 14/10/2012 - I was unable to solve this.  I ended up having to resort to manually creating the menu through Joomla menu.  Not an ideal solution as the menu is not dynamically created, however the menu looks better (as it takes on template style, unlike the Vm Category Module) and most importantly all of the links to all of the categories work!]