it is reported that Gingerbread upgrade has been pulled by Google. the mentioned rom, I9000XXJVK, which was available in UK via Kies, was pulled off
below is an extract from the message posted by an administrator from Vodafone:
Due to an issue with the Gingerbread update for the Samsung Galaxy S, its roll out has been temporarily suspended by Google... we are working with Samsung to reinstate the roll out as soon as possible...
on the other hand however, some people claimed that it was due to a call delay bug on incoming and outgoing calls in 2.3.3