Spymemcached Incr Issue

I use spymemcached 2.6rc1 in my Java project where I want to use the Long class as a storable object. Unfortunately, when I store e.g. new Long(0) object, the get(...) and incr(...) give the wholly different results - get gives Long object that contains 48 value and incr gives 1. Please note that 48 represents the ASCII "0" symbol. When I try to get the value for the same key directly from memcached (e.g. by using telnet) I get the correct result - 0. Strange, the Long is good serialized class. So, probably, there is some problem with default transcoding. Can somebody clarify how to resolve this situation?

http://stackoverflow.com/questions/5928964/spymemcached-get-and-incr-methods-give-wholly-different-results