RoboHelp overwrites table formatting code when importing htm files

I am using RH8 and have installed the patch up to 8.0.2.208.  Most of the files for the project are htm files that are being imported.  These files include tables formatted using <table style=”border-collapse: collapse” width=”100%” border=”2” bordercolor=”#dddddd”>.  The files display fine with a single (collapsed) border before importing to RH. However, after bringing them into RH (or copying/pasting the code), the tables are automatically being reformatted with an additional ‘border-collapse’ clause.  The statement is automatically changed to the following: <table style=”border-collapse: collapse; border-collapse: separate;” width=”100%” border=”2” bordercolor=”#dddddd”>.  The result is a table with a double (separated) border.  Can anyone explain why RH adds in the additional information that over-rides the original code and adds in the ‘border-collapse: separate’ code?  Other than creating a style sheet with a class statement, is there anything in RH that can be set to avoid the automatic change to the code upon importing the htm files?  Thanks, AdjunctInstr2000