Do these buttons just contain the URL you specified above or are they going to a code page or doing any other javascript stuff before heading to that URL?
Have you tried setting the reports up to accept user input or "ask the user" on each field you want filtered and then sending them to the report that way? I'm not sure if these survive going to the next page but they should. I know this isn't a solution to your exact problem but it might help you limp along until you can find a solution.
So for your URL above it would be something like this where v0= is the first field you are asking for user input on, then if you wanted more they go up as you would expect the next would be v1=:
?a=q&qid=272&nv=1&v0=299008&v1=1&v2=100
Then on the actual report you would set the filters to "ask the user" and set them up how you want them to behave as well. As in setting the fields to "is equal to" and getting the and/or's set up properly.
Qrew Legend
