RSS for some collections does not work

I checked RSS for my own collections and received “500 error”
For example,
RSS for Скороговорки и чистоговорки (Russian Tongue Twisters) - LingQ Language Library is Скороговорки и чистоговорки (Russian Tongue Twisters) (HTTP 500 - Internal Server Error)
While “Rasana’s Corner” (http://www.lingq.com/learn/ru/store/36006/ ) RSS works fine Rasana's Corner

Also RSS does not work for
http://www.lingq.com/learn/ru/store/43401/

I wonder what is wrong with these collections… Perhaps, description is too long…

RSS does not work for collections without images

Thanks, Rasana, for pointing this out. We’ll try and get that fixed.

Rasana, this should be fixed now.