Vista - Flight Sim X 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 did a complete defrag using O&O pro and downloaded the reg defrag software
using the link on this site and my FSX popped right up and appears to be running fine.
It looks like my system reg was really clogged up.

Anyway, thanks to all who looked at this.

Regards
Ernest

Good to hear you sorted it

Me too. The thought of un-installing and re-installing FSX was not something I wanted to do. It must have been some left over junk from add-ons etc that got lost or something. Lets just hope that is the end of it.
Thanks for your reply.

Hi, I have te same problem after I installed an add-on. I already did a complete defreg using the defrag software in vista. But which reg defrag software did you use? I tried Registry Clean expert, but it still doesn't work. I already reinstalled FSX acceleration but that didn't work also. I hope someone can help me, so I don't have to reinstall all of FSX