Mail Rules Are Not Being Saved After Mail Is Close & Opended

Question

I am using Mail 3.6 with 10.5.8 on a Macbook Pro. I have set up mail rules so that an email from a specific person's email address goes to two places: 1) Move to a folder on .Mac & 2) the Inbox on the Mail app. Upon first setting this up it works. BUT when closing and opening the program or waking up the computer from a sleep status the rule disappears and the Rule Preference window shows that email message is now going only to the .Mac folder & none to the Inbox!
I spent a lot of time with Tech Support via telephone and even ended up reinstalling (A&I) OS 10.5 (plus updates); this was done on the tech's theory that Mail was corrupt on the root level. HOWEVER, that was not the solution as the problem still exists with the reinstalled OS.
Can someone from Apple's tech support who has knowledge of this issue please help?
Thanks,
Bob

Answer 1

Since replies to questions and comments in these Discussions
is mostly from users who are registered to post & reply here,
you may find better result in a call into AppleCare support and
if there is an incident or case number involved in the issue you
have experienced with corrective actions taken so far in your
communications with Tech Support(?) by phone, be certain a
reference is made to that conversation, for proper follow-ups.
+{You could refer someone you talk to there, to your post in here.}+
There may be some other issue, perhaps relating to hardware
or something else, that may bear looking into. Have you seen
a result of the system log files and reports, such as Console
generates from the computer in action? There may be a clue
in those almost cryptic reports. Also, you have a hardware test
on bootable partition in the original system install disc; that's a
specific test version for your computer, an Apple Hardware Test.
Boot instructions are on the disc's label. Run it in a repeat-loop.
Is there any third-party software installed later on, which could
result in complications or conflicts with the Mac's Mail app?
The problem, if not software, could be hardware. Or a logic error.
If you have AppleCare coverage in effect on the computer, that
is the call to make; and keep track of your incident/case number.
Good luck & happy computing!