PPX on Version 7.3 MR3 and Adobe 7

[GoWestGw]

Upgraded from MR2 to MR3 a few weeks back and have a lot of reports where performance is dire since the upgrade.

They are quite complicated reports on top of a 700mb cube but in MR2 they took 1-2 minutes maximum running time, to produce a 50page PDF of size 1.5mb.  Using MR3 it takes forever.

The reports open in PPClient connected to the remote cube in seconds, although I will say that paging to the bottom of the report takes a while, as does saving as 'PDF'.

Server is Windows 2003, dual processor with 8gb of RAM.

Any ideas or performance advice?