I have a MAJOR problem with the VirtueMart extension. I am hoping someone can help me.

Some products have the correct SEF URL's and some don't.

Empty URL's with Purge SEF Url's and returns to work but 10 days after it fails again

Does anyone have any idea why this is happening?

I'm desperate! Thank you!

Hello,

most likely, there is some "wrong" link that will generate EXACTLY SAME SEO URL as was the original one and will take priority over it. (this happens if you have "prevent duplicates" set to YES, which is recommended)
To confirm this, go to JoomSEF URL manager and check for the problematic SEO link - most likely, you will see there are more variants of it.

You have 2 options:
1) identify the source of this invalid link (you will find it in the URL manager) and if you turn "URL source tracking" to YES, you will be able to see what component is producing the link and hopefully, you can then identify the line in source code and make fixes

2) second variant is not removing the problem, but "selecting" the original non-seo URL that is used for particular SEO URL - this is also made in URL manager, by clicking the "Activate' icon next to the preffered SEO URL

I hope this will help.

Ok, thanks.