now when i log into sl all i can see is gray and blue objects

i think its since the last update but when i log into sl now, all i can see is gray and blue objects that look like the land and the hills etc, what is going on, the last 2 nights about 7pm uk time i have had this problem for about 3 hours of trying,(it cleared up last night slowly after hours of trying) i have been on sl today without any problems, but tonight when i logged in the problems back again, please help, is this a known issue??
gray brennan resident.....

please see attached picture of what i am seeing when i now log in...

Moved to Technical Issues -- could you please give details about your hardware and make sure it meets the System Requirements?

yes my details are pentium 4 2.5 mhz, 1gig ram, ati radion 9000 series graphics, i have had no problems with second life until after the last update, sometimes it works sometimes i have the above problem and when it happens it can take hours for it to work again, also the last few days it has been working again, but today 4th october the grid was down, so when it went back up i am again getting this problem the gray and blue shapes and thats it nothing????? what is the problem, i am a paying resident so this should not happen? when i talked to a linden in live help they said this was a known issue, so please what is the problem?