We found a situation where the client iterates through a list of documents in a folder, unfiling them one by one. (Atompub 1.0 binding)
After the second iteration the client will hang and timeout. (server is ok)
Increasing the .Net runtime's ServicePointManagerDefaultConnectionLimit
from default of 2 to X will move the problem to iteration X. (i.e. increase to 10 and hang will happen on iteration 10)
Reproduced this with FileNet server and with inMemory server to verify it was not something vendor specific we were doing.
Will attach sample .net client code in case you need to reproduce this locally. See LOOK_HERE label in sample code for exaction location of hang.