How Did Kepler Die?

A bloke in the pub yesterday told me that Johann Kepler died by alcohol poisoning in a drinking contest - he was so adamant that the story was true that I thought that he was going to cry so I believed him in my drunken state. I was just wondering if that was actually true and if he merely tricked me to get up in my ribs...

...from nasa.gov

Johannes Kepler died in Regensburg in 1630, while on a journey from his home in Sagan to collect a debt. His grave was demolished within two years because of the Thirty Years War. Frail of body, but robust in mind and spirit, Kepler was scrupulously honest to the data.

All I ever found was that he died of an illness. Which could have been alcohol poisoning, but not necessarily, by any means.