[TYPO3-shop] Problems after upgrade to 2.6.1

[Felix Buenemann]

Hello,

I just begun redesigning a tt_products shop for a client.

The system was running Typo3 4.1.7 and tt_products 2.5.1.

I have upgraded to Typo3 4.2.9 and tt_products 2.6.1.

After upgrading to 2.6.1, I only see 3 products in one category. All 
other categories show as empty.

If I downgrade to 2.5.13, everything is working as expected.

Best Regards,
    Felix Buenemann