Older projects (c 6 & 7) hang in Cubase 8

Just last week I purchased the new Cubase pro 8; upgrade from 7.5, from 7, from 6.5 from 6, from 4/5.
I had to upgrade my Vista to win 7 32b, which I did. A lot of work. Installed the Tascam US 122L with the 2.0, 32 bit drivers.
Only installed Cubase 8 but after 5 min. or so it hangs. Can do nothing with it. Yes eh… have to wait 30/45 seconds every mouseclick. Then I shut it down. It seems not to work with the older projects that I made in Cubase 6 and 7 etc. New projects work just fine; no latency.
The Tascam is installed perfect.
Who has the same issues?
PC is a Medion 2.4 quadcore… strong enough.

Greetings

Vince

I would guess you are running out of memory, 32bit does not leave much room for the project. I can open projects made from Cubase sx3 and up without any problems, besides the missing plugins.