This is a weird coin, some tell it is a pattern, others say it's a normal circulating coin.

Here are my two examples:

1:


2:


They look the same at the first glance, but when examined closer they have several differences:

The first coin seems to be cupronickel plated steel, while the second looks like it's only steel.
Coin #1 has clearly different colour (more like the other nickel plated Uzbek coins) and on
the rim you can see parts where there is no plating (like in US nickel coins or Russian 5 roubles).
The colour difference isn't clearly visible in the scans.

There are diffenrences in the coat of arms too: coin number 1 has full sunrays behind the mountains,
but on the coin 2 they look as if they were fading from the beginning.

The reverse is interesting too, #1 has considerably longer sunrays than the #2.

The most interesting part is, that I've only seen coins like the #2 before. See for
example molotok.ru and you'll only find ones with fading sunrays in the coat of arms and short
sunrays on the reverse.

Is this something new , or did I just rediscover something that's been known for ages?

Very interesting Tane. Metal prices actually rose since 2003 so I wouldn't be too surprised if Uzbekistan did try to save from the very beginning. If I am not mistaken, Uzbekistan does not have a mint and the coins have to be imported from neighboring countries such as from Kazakhstan and Russia. I think some of their bimetal coins were struck in St. Petersburg.

From what I see, Uzbekistan seems to have a lot of varieties so I can't comment on it at the moment. Their central bank homepage which seems to keep changing a few times, is this one at the moment: http://new.nbu.com/ I might be terribly wrong but I can't find any others at the moment.