Windows does not allow : characters in filenames.
http://msdn.microsoft.com/library/en...ing_a_file.asp
Use a date/time format that doesn't include such characters. You can use one of the system script function helpers.
http://www.visualbuild.com/Manual/sysscriptdatetime.htm
For instance:
[vbld_FormatDateEx(Now, "yyyy-mm-dd HH-MM-SS AP")]