I have the exact same issue.
The product installed OK, but when I choose "Start 30 day trial" I am simply told "A problem was encountered..."

The download is from Adobe web page, 15 August 2008.

File size 459.188.632 bytes, MD5 = 27d34a3d4e5c5f08992b74c9747f4280
Payload code = 24D77A7C-E10B-4057-9974-FAB8BFDAC853
Payloads/Setup.xml: 458H Setup version="1.0.135.0"

The software was installed on a fresh PC 2GHz, 1Gb memory, with win XP.

It is totally frustrating that not even a trial can start. At least Quark gets that one right.. I truly understand people that search for a key generate online. All I needed was a trial while I wait for my paid copy to appear.

Btw: InCopy will not even install, here I am simply told: "You can only run one installer at a time".. although InDesign was already completely installed.

Shame on you, Adobe installer team. Shame on you.