[Full-page]_[2col-rightSB]_[2col-leftSB]_[3-col]: Bulletproof assistance?

[mhulse]

Hey all,

If you do not mind me asking... how close am I to making these pages bulletproof (i.e. how are my CSS hacking skills)?:

[The CSS]
[3col]
[2col(Left Sidebar)]
[2col(Right Sidebar)]
[Full Page]

I have only been able to test the pages on a Mac/IE(v5.2) and Mac/Safari(v1.3)

I would love some feedback concerning cross-platform/browser compatabilities and (in)consistencies with my code. I am just learning about how to filter my CSS to make it do what I need it to do... but some things are still very unclear... again, I would be extremely happy to get some help on this one.

Many thanks in advance!
Cheers,
Micky