3.5.3 patch 3
The Serialisation is done correctly. Geting the objets back from the cache has the correct time with the milliseconds.
I suspect it has something to do iwth Coherence*Extend and useof IComparable in filters.
Did you find a resolution to your problem with the DateTime filtering? I am having similar issues in that my filter is returning me back everything from the cache regardless of the time filter I placed on my query.