Secure Connection-random pickup and drop

Question

I am using a linksys SRX router running WPA personal encryption and my SSID is not broadcast. There is one windows desktop and 2 mac laptops on my network, all connect wireless.
Now for my problem...
On starting up my laptop it will normally find my network and connect no problem. When I close the lid (putting it in sleep) and re-open it about 50% of the time it will NOT automatically connect to the network.
A couple of strange things:
1) The problem seems to be getting progressively worse(My MBP is only 2 1/2 weeks old). The first 4-5 days I had no problems at all. Once it started happening it seems to be more frequent as time continues.
2) When the problem first happened simply turning the laptops airport off then on fixed the problem.
That stopped working and I had to add another step in the process by clicking on my wireless icon and selecting my network. (even though it already was checked)
Now if that simply fixed it I would not be so bothered, unfortunately that method of 'fixing' it stopped working tonight.
When I tried to use my normal 'method' tonight, my network name was no longer in the drop down menu.
I then selected 'Open Internet Connection...' in the menu and configured my network. This still was not fixing the problem.
So i go into the 'network' tab and 'configure', and my network is the first in the default network section.
The only thing that seems to 'fix' the problem now is to click on the 'assist me' tab and run 'diagnostics'. When i do this, it prompts me for my network info and then connects immediately once its entered.
Sorry for the extra long post I was trying to explain the problem and how i currently 'fix it' as thoroughly as possible.
quick recap- when i close my lid and open it up my laptop only connects to my network half the time. On startup it connects 80% of the time.
The 'fix' for me to connect has gotten longer and more complicated....please help me
MBP, 2.33ghz Core2Duo   Mac OS X (10.4.8)   also runs windows

Answer 1

Does'nt seem to matter what router you have, because Apple blame every body else's equipment - this is their advise:
Mac OS X 10.4.8: Intel-based Mac can't obtain IP address from third-party wireless router
Symptom or Issue
After installing the Mac OS X 10.4.8 update, Intel-based Macintosh computers may not be able to obtain IP addresses from some third party wireless routers.
In this event, the Mac is generally able to associate with the wireless network, but it will obtain a self-assigned IP address (169.254.x.x) and will not be able to connect to the Internet.
Products affected
Mac OS X 10.4.8
All Macintosh computers
Solution
Turn the wireless router off and back on.
Note: This step will disconnect any clients currently connected to the wireless network provided by this router.
If restarting the router does not resolve the issue, contact the manufacturer of the third-party wireless router to resolve this issue.
The last sentence says it all - its somebody else's problem!
My MBP C2 does the same!!
All my other Mac work perfect with Netgear DG834G, My MBP C2 does not, so it seems to me its the Apple MBP C2 that has the problem not third party equipment - so Apple get your finger out and solve the problem.....