With great sadness we have to announce that we are ceasing development of all our VirtueMart, WooCommerce and Joomla plugins. Effective immediately, all our plugins -- even those that were paid downloads -- are made available for free from our homepage (GPL license still applies), but we cannot and will not provide any support anymore.
It has been a great pleasure to be part of the thriving development communities of VirtueMart as well as WooCommerce. However, during the last year it became painstakingly clear that in addition to a full-time job, a young family and several other time-consuming hobbies at professional level (like being a professional singer) the plugin development and the support that it requires is not sustainable and is taking its toll. It has been an honor, but it is now time to say good bye!
I am developing the plugin with PHP 5.4 on Joomla 2.5 with VirtueMart 2.0.
Other combinations might work, but I have not had any reports. If you are using the plugin on a different combination of versions, please let me know whether it works or not.
Currently, I'm not aware of any incompatibilities with certain Joomla or Virtuemart versions, or with other extensions.
I'm always open for good suggestions and ideas concerning the plugin's functionality. However, as my time is really limited, I cannot promise anything. Currently, the following ideas are on my list:
I have no idea when I will be able to implement these ideas. If you really need any feature urgently, please feel free to ask me for a quote for custom development. All commissioned features will of course be made available to all other plugin users, too, if they are useful to the general public.
The download plugin uses custom fields attached to products, and there are two different types of custom fields: Cart variants and Non-Cart variants.
If you choose "Yes" in the custom field configuration page (i.e. you create a cart-variant, which means that to VirtueMart the custom field describes a distinct feature of the product), then the custom field (the download button) will be displayed together with the price on the product details page and just below the product name in the order view and the invoices.
On the other hand, if you choose "No" (i.e. you do not create a cart-variant), VirtueMart understands the custom field as just some additional information to the user in the online shop. Thus VirtueMart does not deem it neccessary to display any information from the custom field in the invoice, and will place the custom field's output at the bottom of the product details page.
So, the short answer to the question is: You did not make the custom field a Cart Variant. Change this in VirtueMart's custom fields admin page.
To be honest, I have no idea. I have never tried K2mart and I don't have access to a copy of it.
Judging from the description on their homepage, I would guess that the links in the order/invoice are the standard virtuemart views. Likewise, the "My downloads" area is provided by the plugin, so that should work,too.
The product details view, however, appears to be overridden by K2mart with its own view. There it depends on how well K2mart handles custom fields.
So, in short: I cannot really say whether it will work for you or not.
I would be really glad if someone with K2mart could give me some feedback whether it works or not.