Sorry, I don't have enough time to do that. But you can buy our paid support services and we assign you a developer who will fix your problem.
Otherwise the only way will be probably to start from scratch.

Oh ok. Only offered as I thought that would be quicker than trying to replicate in your own system.

Guess I'll just figure it out myself then.

Let me know if you find something that could cause it.

I think I may be onto something...

When I disabled the virtuemart main menu item that linked to my the shop category, and instead installed the virtuemart module (mod_virtuemart), a few differences are notice:

(btw, I purged all existing again after making that change, then refreshed the page)

- the SEF link to the category (based on it appearing in the module rather than the menu) is now "home/2009-collection" (I assume it picks "home" to append to since there's no virtuemart menu item anymore)

- the "Show Cart" link in the cart module is no longer replaced by a SEF URL (its just the standard "index.php?page=shop.cart&option=com_virtuemart&Itemid=1")

- every product SEF URL is now "home/<productname>" instead of "category/<productname>"

- the "previous/next" product navigation links are now all getting the correct SEF URL


Most interestingly, the Prev/Next links and Show Cart link break again the moment I enable that virtuemart menu item.

Does that give you a hint as to what is going wrong?

Got it!

I've found what it's not happy with...

If you set either a Product ID or Category ID in the menu item (in "Parameters (Component)"), it doesn't like it.

For everything to work, if you have one or more virtuemart menu items, one needs to have just the default settings (ie. no IDs, flypage, etc set).

So how do we get that behaviour fixed?

Sorry, I tried this as well, I set Product id, Category id, both, than Purge URLs and it always worked.Only Show Cart doesn't have SEF url.