Amazon possibly slowing down package processing

[ale_fernandez]

Hi, We have magento 1.9 and are using m2epro for amazon and are integrated with royalmail. When an amazon related package gets processed, the whole website slows to a crawl sometimes for 4 minutes at a time. I'm trying to debug it and suspect there is a lock happening in the database.. So 

1) has anyone had this issue with amazon? It may be royalmail which is also slow sometimes, but it might be unrelated...

2) Does anyone know how I can find out what queries are run by that plugin(it has lots of tables!) during the package fulfillment process?

As it's a live server I can't switch on mysql query logging without affecting it.

Thanks for any clues!

Alejandro

[ale_fernandez]

Just to say I've now begun to log the results of lines like 

Mage::log((string)$collection->getSelect(),null,'test.log',true);

But to no avail so far..