Java HotSpot Virtual Machine

Hello everyone,
I've got something going quite wrong with a simple method, crashing the JVM with the exception :

# An unexpected error has been detected by HotSpot Virtual Machine:
#
# EXCEPTION_GUARD_PAGE (0x80000001) at pc=0x7c920c27, pid=880, tid=1760
#
# Java VM: Java HotSpot(TM) Client VM (1.5.0_09-b03 mixed mode)
# Problematic frame:
# C [ntdll.dll+0x10c27]
#

The C++ code :

char *temp;
_bstr_t sum, aut,stat,prior,ass;
for (long i=1; i <= bList->GetCount(); i++)
{
					
	mybug = bList->GetItem(i);
	if(mybug){
	                sum=mybug->GetSummary();
			aut=mybug->GetDetectedBy();
			prior=mybug->GetPriority();
			ass=mybug->GetAssignedTo();
			temp=(char *)LPCSTR(sum);

The last line cause the problem. The GetSummary really return a bstrt.

The really strange thing is that this code works fine in a class test but doesn't integrated in my Struts application.

Any ideas where it could come from ?