Fujitsu with D-Link - startup problem

I have a Fujitsu Seimens Amilo Pro V2000 with built in wireless. My wireless
router is a D-Link DSL-G604T. Although I have set wireless to be on by
default (Bios setting) and therefore don't need to press the wireless
connect button, when I first power on the laptop it usually won't find the
local network even when I go into the network manager and 'Refresh network
list'. Sometimes the connection does come after a few minutes. The
solution I've found is to flick the laptop to standby for a few seconds then
go back in and it finds the network instantly. Any ideas why this is, is
this a hardware quirk or do I need to tweak some settings?

Any tips appreciated. Steve

P.S Please reply to group.