After rebuilding an app with Boost 1.35 (using Visual Studio 2008/VC9 [creating a 32-bit Unicode executable] on Windows XP SP2), some code (only in a release build) calling string_algo causes assertion failures at iterator_range.hpp lines 265 and 283 (iterator_range::begin and iterator_range::empty). The assertions are a result of calls to replace_all and istarts_with (in 2 places; each call in different functions and called multiple times from a single thread; thread data used in the calls is private to this thread). If all of these calls are removed: replace_all(<wstring variable>, L"/", L"\\"); if (istarts_with(<function returning wstring>, <function returning wstring>) return; if (istarts_with(<wstring variable>, L"www.")) <wstring variable>.erase(0, 4); the assertions do not occur. If any or all are left in, some assertions occur. When building w/ Boost 1.34.1, the original code works as expected with no assertions. Before I try to construct a repro case, does anyone have any ideas on what could be wrong? Thanks. -- --------------------- Kyle Alons http://www.kinook.com