Microsoft has documented occurrences of occasional file corruption with Windows NT versions 3.51, 4.0 and 4.0 Terminal Server Edition. According to the Microsoft knowledgebase article (at http://support.microsoft.com/support/kb/articles/Q169/6/08.ASP?LN=EN-US&SD=gn&FR=0, article #Q169608) file data may be read incorrectly or files may be corrupted due to data caching conflicts. According to the article, the problem may be resolved by installing the appropriate service pack.

Please follow the link to the article for additional details and make sure your Windows NT system is in compliance!