cubase 4 halion 2 old projects crash

Original pc xp 32bit - new pc win 7 64bit.
Installed cubase 4 & halion 2 and trying to open any project referencing halion causes cubase crash.
If I hide halion - project will load.
New projects save & reopen OK.

Would be grateful for any ideas on how to proceed.

Crash details are:

Cubase4.exe Version Version 4.5.2 Build 274 - 8.3.2012 8:55

Timestamp is 48bd9c13 (Tue Sep 02 21:03:31 2008)

Exception code: C0000005 ACCESS_VIOLATION
Fault address: 00CBEC72 01:008BDC72 C:\PROGRA~2\STEINB~1\CUBASE~1\Cubase4.exe

EAX=00000000 ECX=10bf2404 EDX=015a25d0 EBX=00000009 ESI=0018f7f0 EDI= 06be4fb8
EBP=0018ed4c EIP=00cbec72 ESP=0018e284 CS= 00000023 SS= 0000002b Flags=00210246
DS= 0000002b ES= 0000002b FS= 00000053 GS= 0000002b

Float Save:
Control Word= 0000027f Status Word= 00000120 Tag Word=0000ffff
Error Offset= 0a8b7359 Error Selector=00000023
Data Offset= 0018e19c Data Selector= 0000002b
Cr0NpxState= 07b2e3b8

Bytes at CS:EIP:
8b 80 e8 01 00 00 c2 04 00 cc cc cc cc cc 53 8b
5c 24 08 56 57 8b f9 8b 8f 3c 01 00 00 8b 01 8b

Call stack:
Address Frame
00CBEC72 0018ED4C 0001:008BDC72 C:\PROGRA~2\STEINB~1\CUBASE~1\Cubase4.exe
00C12685 0018F704 0001:00811685 C:\PROGRA~2\STEINB~1\CUBASE~1\Cubase4.exe
00C145E8 0018F848 0001:008135E8 C:\PROGRA~2\STEINB~1\CUBASE~1\Cubase4.exe
00DFC3C5 0018F874 0001:009FB3C5 C:\PROGRA~2\STEINB~1\CUBASE~1\Cubase4.exe
0061A508 0018F894 0001:00219508 C:\PROGRA~2\STEINB~1\CUBASE~1\Cubase4.exe
00F1A875 0018F8F4 0001:00B19875 C:\PROGRA~2\STEINB~1\CUBASE~1\Cubase4.exe

No suggestions - mods, support?