Pagination sequence 404 errors

[en jie rudd]

Hello there

We have not long ago upgraded to Joomla 2.5 Vm 2.0, currently getting numerous pagination sequence related 404 errors:

example 1 (sh404sef):
sef url: /dirdesc/results1-10
non-sef url: index.php?option=com_virtuemart&Itemid=59&dir=DESC&keyword=&lang=en&limit=10&limitstart=0&view=category

example 2 (google webmaster tools):
url: http://www.valleygreentea.com.au/tea-demonstrations/Page-1.html?fontstyle=f-smaller&task=view
linked from: http://www.valleygreentea.com.au/tea-demonstrations/Page-2.html?fontstyle=f-smaller&task=view

Would really appreciate if someone can help to point out what the cause is and how to fix it.

Any help is greatly appreciated and desperately needed. I am also happy to pay a fee if needed.

Joomla 2.5
Virtuemart: 2.0.26d
PHP: 5.4.28

Thank you in advance.

regards

En Jie