Ok, I am getting server timeout when I try to view a report of try to run reports from the control panel.
This was working fine since 8/8/2010 with version 4.3.2. I have not been able to access these reports since 4.3.6.
this weekend I resent email for the client. first batch about 3000 sent flawlessly, tried to generate view report "works Fine" move to control panel to run reports. server error 500.
second batch about 7000 sent flawlessly, tried to generate view report "server timeout" move to control panel to run reports. server error 500.
Again all this was working fine as of 8/8/2010

View report is a problem but not been able run any reports at all is a very bad problem.

I use the scheduler for sending
WS 2003 Standard
MS SQL 2005
DNN 4.9.4

I have another dnn instance with optin email (4.3.2) but not with enough email subscribers to reproduce the test. 

Could it be something I have done? Can I go back to 4.3.2? Unfortunately I can't restore from a backup way too many things have changed.
Any help will be greatly appreciated.

Please see previous posts for more details.

Just wanted to let you know I have made same changes to the web config file that took care of the "view report" timeout.
Sys.WebForms.PageRequestManagerTimeoutException: The server request timed out. still exists when I try to run reports from the control panel.
 .
FYI the following steps are also suggested for Catalook:
Change this line in your web.config: <form>s name=".DOTNETNUKE" protection="All" cookieless="UseCookies" timeout="60" /> to <form>s name=".DOTNETNUKE" protection="All" cookieless="UseCookies" timeout="600000" />
Add green marked parameter to the httpRuntime section of the web.config and change the red marked parameters:   maxRequestLength="2097151" requestLengthDiskThreshold="50000" executionTimeout="9000" />
Some Hosting providers also restrict the time on the server side. In this case please ask your hosting provider to remove the timeout restrictions. Here you can find more information: Timeout Error

Thanks for sharing this, Franc!

Unfortunately
Sys.WebForms.PageRequestManagerTimeoutException: The server request timed out.
still exists when I try to run reports from the control panel.

Also, View Report take much longer to process than it use to.