Joaquin hi, I've opened your project in VS2005, added the required lib files (libboost_date_time-vc80-mt-s-1_41.lib and libboost_date_time-vc80-mt-sgd-1_41.lib) which I compiled especially for this test, and besides the additional directories I've changed the property RuntimeLibrary which I set to be "0" [Project properties -> Configuration properties -> Code Generation Runtime Library <= Multi-threaded(/MT)]. I was surprised twice: 1. I've executed the program with no difficulties (didn't reproduced what you've mentioned about endless loops). 2. I didn't reproduced the initial problem which I've complained about (the assertions). Which makes me think that this a result of the VC9 compilation. I've did those tests with several boost versions (1.35,1.39,1.41) and reproduced the problem in 100% of the cases, but always compiled with VC9 compiler, changing the compiler is not in option in my case therefore I must find a solution to this problem. I'm glad that now I might be more focused about where the problem is, but have no clue in how to solve it. Any new ideas ? Eli Zakashansky. ________________________________________ Your project is for MSVC 9.0, alas I've got MSVC 8.0 here. I've rebuilt with static linking and the problem persists. Maybe you can take a look yourself, please find attached the MSVC 8.0 solution, which hopefully you can open with MSVC 9.0 See the same there? Joaquín M López Muñoz Telefónica, Investigación y Desarrollo