Mail app won't open New/compose page

Question

In Mail I receive incoming msgs but, when I click on "new" msg or "Reply" (to msg received}, nothing happens. ISP/server is Insight Broadband. Insight says it is Apple problem.
Appreciate any INSIGHTS.
DON H.
imac Pwr PC G4   Mac OS X (10.4.7)  

Answer 1

This particular problem in Mail is usually caused by some Launch Services cache or preferences corruption. The following article describes how to manually reset Launch Services. The notes at the bottom of the article also provide information about the side effects of deleting each of the files involved.
Resetting Launch Services
The following article also describes the side effects of cache cleaning:
Side effects of System cache cleaning
The following article provides links to some utilities that can be used for troubleshooting and cache cleaning:
Resolving Disk, Permission, and Cache Corruption
It seems that the most appropriate utility for solving this particular problem is Tiger Cache Cleaner.
In addition to the utilities mentioned above, you may also consider OnyX, which is free. If you want to try OnyX, after installing it, do this (be sure to read the articles about the side effects of cache cleaning first):
1. Quit all applications.
2. Launch OnyX and enter your administrator password.
3. Click Maintenance. In the Reset section, check LaunchServices database.
4. You may uncheck any other pre-checked options if you've already done them using other utilities.
5. Click the Execute button.
6. Restart.
If that doesn't solve the problem, you may try again checking the Links between documents and applications option in step 3 instead.
And yet another free cache cleaning utility is Cache Out X.
Please, let me know whether you were able to solve the problem, what worked for you and what didn't.