Win 7 is listed beginning with FMP ver 10 - this is a minimum system requirements
FileMakerPro System Requirements and Compatibility - All Versions
Answer ID: 4701Last Updated: Sep 26, 2012
FMP 8.0 Compatability
posted November 6, 2009 by TSGal
Only FileMaker Pro 10 has been tested with Windows 7. Please see Knowledge Base Article #7453 for the latest information about Windows 7 and FileMaker Pro:
The system requirements for FileMaker Pro 8 do not include Windows Vista. However, many users appear to be using it successfully. FileMaker Pro 9 was the first version to be certified running under Windows Vista.
Others have reported this issue. The solution is to upgrade to a newer version of FileMaker.
Thanks for comments - not the answer that I was hoping for, but not totally unespected. Will probably stick with the "problem" as it is too small an inconvenience and I don't use FileMaker enough to be able to justify an upgrade.
You might try using "xp compatibility mode" to see if that avoids the issue.
I have found a solution that doesn't involve having to buy a newer version of Filemaker - and the interesting (though slightly worrying) thing is that I found it on the Filemaker website!!!
This page details an update to FileMaker 8.5 which gives two key beneifts one of which is "The window no longer turns black when it redraws in Browse, Find and Layout modes. "