Is 2.6 ledger format compatible with 2.4?

[Michael Carney]

Is it safe to downgrade gnucash to 2.4 if my ledgers have been updated 
by 2.6? I've been seeing instability in 2.6 (appear to be gtk problems) 
plus the CAD account issue I mentioned.

Thanks.

FYI:

[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Missing separate debuginfo for /lib64/libgraphite2.so.3
Try: yum --enablerepo='*debug*' install 
/usr/lib/debug/.build-id/90/82e46860379c3dff9004eb8c9834e50afbb528.debug
Core was generated by `/bin/gnucash --nofile'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x000000312487fc7a in IA__gtk_widget_queue_draw (widget=0x5303080)
     at gtkwidget.c:3779
3779      g_return_if_fail (GTK_IS_WIDGET (widget));
...
(gdb) info all-registers 

rax            0x12768d0        19359952 

rbx            0x5303080        87044224 

rcx            0x0      0 

rdx            0xe00    3584 

rsi            0x2      2 

rdi            0x5303080        87044224 

rbp            0x53032f0        0x53032f0 

rsp            0x7fff43640850   0x7fff43640850 

r8             0x117cac0        18336448 

r9             0x30     48
r10            0x0      0
r11            0x22     34
r12            0x1f     31
r13            0x3d     61
r14            0x15b    347
r15            0x13     19
rip            0x312487fc7a     0x312487fc7a <IA__gtk_widget_queue_draw+42>
eflags         0x10206  [ PF IF RF ]
cs             0x33     51
ss             0x2b     43
ds             0x0      0
es             0x0      0
fs             0x0      0
gs             0x0      0
...
(gdb) disassemble $rip
Dump of assembler code for function IA__gtk_widget_queue_draw:
    0x000000312487fc50 <+0>:     push   %rbx
    0x000000312487fc51 <+1>:     mov    %rdi,%rbx
    0x000000312487fc54 <+4>:     sub    $0x20,%rsp
    0x000000312487fc58 <+8>:     mov    %fs:0x28,%rax
    0x000000312487fc61 <+17>:    mov    %rax,0x18(%rsp)
    0x000000312487fc66 <+22>:    xor    %eax,%eax
    0x000000312487fc68 <+24>:    callq  0x3124874f50 
<IA__gtk_widget_get_type>
    0x000000312487fc6d <+29>:    test   %rbx,%rbx
    0x000000312487fc70 <+32>:    je     0x312487fc8e 
<IA__gtk_widget_queue_draw+62>
    0x000000312487fc72 <+34>:    mov    (%rbx),%rdx
    0x000000312487fc75 <+37>:    test   %rdx,%rdx
    0x000000312487fc78 <+40>:    je     0x312487fc7f 
<IA__gtk_widget_queue_draw+47>
=> 0x000000312487fc7a <+42>:    cmp    (%rdx),%rax
    0x000000312487fc7d <+45>:    je     0x312487fcc0 
<IA__gtk_widget_queue_draw+112>
    0x000000312487fc7f <+47>:    mov    %rax,%rsi
    0x000000312487fc82 <+50>:    mov    %rbx,%rdi
    0x000000312487fc85 <+53>:    callq  0x3124666df0 
<g_type_check_instance_is_a at plt>