I've tried these tricks and I'm still only getting 1 WU at a time. this is really annoying that my GPU stops when it finishes a WU then has to wait on a new one to come in. can my cache be set higher?

<app_info>
<app>
<name>milkyway</name>
</app>
<file_info>
<name>astronomy_0.20b_ATI_SSE2_amd.exe</name>
<executable/>
</file_info>
<file_info>
<name>brook32.dll</name>
<executable/>
</file_info>

<app_version>
<app_name>milkyway</app_name>
<version_num>20</version_num>
<flops>1.0e11</flops>
<avg_ncpus>0.05</avg_ncpus>
<max_ncpus>1</max_ncpus>
<coproc>
<type>ATI</type>
<count>1</count>
</coproc>
<cmdline>w0.9</cmdline>
<file_ref>
<file_name>astronomy_0.20b_ATI_SSE2_amd.exe</file_name>
<main_program/>
</file_ref>
<file_ref>
<file_name>brook32.dll</file_name>
</file_ref>
</app_version>

</app_info>

I've just acquired a second Radeon HD 4850 and stuck it into my crunching box:
An Intel Q6600 with 2 GB RAM in an Asus P5B Deluxe, now with two Visiontek Radeon HD 4850's (previously only one).
No crossfire or anything is enabled, as I don't believe I want that, I just want two, separate cards, doing crunching (I do this with two different nvidia cards in my primary desktop and assumed I could do the same with ATI cards).
However the secondary display shows up in the drivers under the hardware tab as "Disabled Adapter", and I don't know how to enable it :/

Related question: a quad with 1 ATI card is limited to a 24 WU cache. If another ATI card is added is the cache doubled to 48 WUs or is the machine still limited to 24?