Help! PT LE+ Reason 3via Rewire on an iMac G5

[ensonix]

I have just bought a 17" 1.8Ghz iMac G5 w/ Superdrive along with an MBox (PT LE v.6.7) . I believe I have Mac OS 10.3.7. I installed Pro Tools and Reason 3.0 with no problems at all.

Now when I try to run Reason's demo song in ReWire, the sound starts but suddenly, the playback stops and I get a message saying that the CPU can't handle it and suggesting I raise the H/W Buffer setting in the Playback setup. Now, I only have three H/W buffer settings: 256K, 512K and 1024K. By default it was at 512K. I raised it at 1024KB and durring playback, I got another message it couldn't handle it however this time, asking me to reduce the H/W buffer setting! I'm going in circles

This is in a brand new PT session with only 1 stereo track and no plug ins at all!

My questions is does anyone other than me having problems running the Reason 3 demo song via ReWire in PT LE with an MBox. Is this normal? I would have thought the G5 capable of much more than this.

I know that there are apparently performance issues with Reason 3 as reported by Propellerheads however, it only seems to mention performance issues when scrolling within Reason 3...

[DigiTechSupt]

In your Energy Saver control panel, make sure all energy savers are set to 'never', uncheck the box that says 'put the hard disk to sleep when possible' and, under the 'Options' tab, make sure that processor performance is set to 'highest'.

It is also strongly advised that you use a secondary firewire hard drive to record and play back sessions from.