Chris,

What method of booting are you using?
I have several HP 5745T Thin Clients as nodes. 27946 and 28263 are both on thin clients.
I chose to make my system boot from the onboard 2gb eeprom. I upgraded the ram to 4gb. I set up a 3gb ram drive.
I load the ISO image into the ram drive at boot time.

When I first setup my thin client I used an external hard drive plugged into the expansion port on the thin client. I then installed ACID and performed an upgrade just in case.

Once I had my nodes working I then created my ram drive system.

I chose this path because even using a small 10gb ssd plugged into the thin client I could not get the system to boot up after install competed.

I did this a couple of years ago. I think the issue was the same as yours.

If you want more detail I will be happy to share my work with you.