Sporadic Network Connection

I have a Sony Vaio SZWNX5 with built in wireless networking and bluetooth.

I have a netgear wireless router and the two have been talking perfectly for
several weeks.

However this last week the laptop has frequently been unable to detect a
wireless network connection on start up. Only a reboot (or two or three) has
resulted in the network being detected. Connecting to the LAN with a cable
instantly fixes the problem so it is obviously something to do with the
wireless network connection (inbuilt).

How do I rectify this? Is it a software issue? Should I use my warranty
support option to resolve the problem or is it likely to be a sofware
compatibility issue? In the last week I have had some automatic software
upgrades installed from Microsoft but that's all...

Another problem that has occurred recently is the inability to paste text
copied from another program (ie from Word to mail or IE to Word, etc).
Nothing happens.

Are these Vista 'features'?

Sorry if these are stupid questions but I'm not a techie ...
Welcome any advice ...
Thanks