You're correct, later Safaris won't run on 10.4.11
Which exact iMac is this?
So we know more about it...
At the Apple Icon at top left>About this Mac, then click on More Info, then click on Hardware> and report this upto but not including the Serial#...
Model Name: iMac
Model Identifier: iMac7,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2.4 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 4 MB
Memory: 6 GB
Bus Speed: 800 MHz
Boot ROM Version: IM71.007A.B0
High time you updated the operating system and thereby also Safari.
Start by checking if you can run Snow Leopard:
Requirements for OS X 10.6 'Snow Leopard'
(NB: PowerPC applications can still be run in Snow Leopard using Rosetta, but they will not work in later versions of OS X.)
The OS 10.6 Snow Leopard install DVD is still available for $19.99 from the Apple Store:
and in the UK:
When you have installed it, run Software Update to download and install the latest updates for Snow Leopard to bring it up to 10.6.8, or download the combo update from here:
Pre-Installed MacOS: X 10.4.7 (8K1106) Maximum MacOS: X 10.7.5*
I'd add more RAM before upgrading the OS version though...
Easy to install...
You must get 10.6 if they still have it, install it & update to 10.6.8 so you have the App Store to buy & download the huge 10.7, but I'd stick with 10.6.8
Snow Leopard/10.6.x Requirements...
* Mac computer with an Intel processor
* 1GB of memory (I say 4GB at least, more if you can afford it)
* 5GB of available disk space (I say 30GB at least)
* DVD drive for installation
* Some features require a compatible Internet service provider; fees may apply.
* Some features require Apple’s MobileMe service; fees and terms apply.
Call Apple Sales...in the US: 1-800-MY-APPLE. Or Support... 1-800-275-2273
It looks like they might still have it...
I am no techie but I just began using Omniweb 5.11.2 on my iMac Cure Duo 20", 2gigs ram, running Mac Tiger Intel 10.4.11. I was having your exact problem with Safari + Firefox so I gave Ten Four Fox Intel 17.0.2 a try but the makers of TFF no longer support it, can be quite buggy, even locking up my computer. Then I seriously began to play with Omniweb which is built on the Safari 5 platform (giving the newest functionality), works perfectly, quick, no glitches so far, was able to import all my Firefox bookmarks, just continue where I left off with Firefox + TFF. There are not many extensions for Omniweb but an excellent selections of Plugins comes built-in. Even though I cannot install the Google Drive software, I am able to use Google Drive from Omniweb which installs the Java applet. Omniweb works perfectly with the Apple keychain so I rarely have to enter USER:PW info. I am writing this reply from Omniweb, give it a try, just might solve your problem. Configuring the Preferences in Omniweb, like all browsers is a learning experience as each has its own unique settings, but you can play with that to your satisfaction. Hope this helps. Ken.