Vista - FSX visualfx.dll error

A bit of background about my problem.
I have FSX w/Accel install on my system.
System specs have been posted.
I found this site doing a google search on my problem.
I use a RAID setup with the os on c and fsx is on d. The drive is partition.
I was getting a problem with smoke and dust effects showing as blocks.
Checking through the various flight sim web sites, the general solution was to do a repair of fsx to solve the problem. I did that and the problem did go away for a time. It came back up about a week ago, so I did the same thing, a repair of fsx and acceleration today. Problem compounded.
Other than that, a complete un-install/re-install. Not something I truely want to. For those of you who have fsx, you understand why.

When I go to start fsx I get the below error msg.

Problem signature:
Problem Event Name: APPCRASH
Application Name: fsx.exe
Application Version: 10.0.61637.0
Application Timestamp: 46fadb14
Fault Module Name: visualfx.dll
Fault Module Version: 10.0.61637.0
Fault Module Timestamp: 46fadb59
Exception Code: c0000005
Exception Offset: 00014857
OS Version: 6.0.6001.2.1.0.768.2
Locale ID: 1033
Additional information about the problem:
LCID: 1033



Sorry if this is long winded, but if anyone has any ideas, please let me know.

Thank you

Regards
Ernest

Problem solved
I downloaded the reg defrag software using the link on this site.
System reg was really clogged up.
Anyway, fsx pops up and appears to run just fine.

Thanks to all who read this post.

Regards
Ernest