VBA Compatibility between Excel 2007 and 2010

Hi

I have 4 Excel workbooks which were created in Excel 2007. Each workbook contain approximately 200 sheets, which contains information of clients. Each workbook has 3-5 VBA routines (some quite long) which were written to do routine work between the workbooks and inside each workbook (depending on the tasks to be completed). Both the sheets and VBA code in all the workbooks were originally created in Excel 2007 (nothing was done in older versions).

Every VBA routine run extremely fast and smooth if run in Excel 2007. A few months ago we upgraded to Excel 2010 and right there everything SLOWED DOWN to a crawl.

The VBA code (when executed in Excel 2010) run 20 times slower than in Excel 2007. At first I though it was something in the VBA code that were written in Excel 2007 which were not compatible with Excel 2010. I then re-created 5 sheets from scratch in Excel 2010, and copied the VBA code to Notepad (from one of the Excel 2007 workbooks) and from there to the VBA module in the Excel 2010 workbook (note - I did not change a single letter in the original VBA code. I only copied it that way to make sure nothing of Excel 2007 could come through together with it). After that I ran the VBA code in the "new workbook" which were created in Excel 2010, and it was as fast as it were in Excel 2007. After three months of "snail mailing" in Excel 2010 I took one of the workbooks and ran it again in Excel 2007, and what do you know - blazingly fast!

Why does this happen? If there was any conflict between 2007 and 2010 VBA code it should not have been faster after I recreated the five sheets in 2010. The amount of sheets in each workbook is also not the problem since it is still running at full speed in Excel 2007 when tested.

It is going to take days to recreated 800 sheets with client information that change almost daily. It's a logistical nightmare which I'm not opting for.

Does anybody have any suggestions / solutions or similar experiences?

Any help will be greatly appreciated!

This post has been cross posted on: http://www.ozgrid.com/forum/showthre...404#post668404

Thank you!