ssrs Report taking to much time to load

Hello all,

I have a matrix report which was running nice before some days, but now taking too much time to load 

i tested store procedure but it is ok to return same data in 5 seconds 

and when i tested in ssrs BIDS side i set 60 sec for dataset timeout option, and it gets timeout 

after i set 1000 seconds timeout but it is just rolling and rolling loading 

when i check in executionlog of reportserver i found  something like ..

TimeDataRetrieval     TimeProcessing     TimeRendering       Status                                                  RowCount

131951   323    95        rsHttpRuntimeClientDisconnectionError    1784

Reply me fast please, Help must appreciated .. 

Thanks ..

Dilip Patil..