Dear Scott
Try Copy and Paste Special command not paste and in Paste Special command you have option to paster format , formula etc. I think that should solve your problem.
Plus you are saying that you get error in Excel File Please clarify that file is not currupted or the source from where you are receing the file there Excel may have some error or it can be virus proble on the other end too.
Try all these I hope your result will be positive.
rahul
Thanks in Advance
Rahul