If the repository has lots of packages it can take time. It seems OSS repo is a 27mb file so should take about 45mins. Only add the OSS and non-OSS repositories, that should be enough IMO.
This might be useful too
http://linux.wordpress.com/2006/12/2...-repositories/ if you've not already seen it.
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And thread title changed, as the previous one was misappropriate.