Whilst they may not sort out your fixed luggage problems I
really recommend these bags:
http://www.ewetsuits.com/acatalog/Dr...s-uk.html#a841
Very, very, waterproof, well made and it's a British firm with quick delivery and bloody good prices.
I have this 40L bag in yellow (get black as they don't stay yellow long!):
http://www.ewetsuits.com/acatalog/mo...g-holdall.html
The 30l is a bit too small (good for overnight) and the 60l, whilst roomy is a bit big on the pillion seat.
I also have this bag:
http://www.ewetsuits.com/acatalog/motorbike-drybag.html Fantastic at �11.50
I used it as a stuff sack with my tent and other camping gear in it.
This is my Tenere loaded up in Tiblisi after riding through a massive rain storm across Georgia. The yellow bag is the 40L - utterly waterproof.
I can't recommend them enough!