First of all... frames? Really? I mean, in 2009, really?
Second, I've attached a PDF of the W3C validator and what it had to say about your frames page. Both of your main HTML files are fine in Opera when loaded individually, so it seems to be something with the coding of your frames. Check the PDF, see if anything in it makes sense.
I'd tell you what I thought if it, but really, I can't even begin to remember the last time I used frames, so I've forgotten everything about that stuff.
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