poderosa connected cygwin error

when I down load poderosa(a excelent ssh client),and this error occured:

"Index was out of range. Must be non-negative and less than the size of the collection.

Parameter name: startIndex""

and I search the source code and Foundout where error occured:

int LocalShell.cs

char[] buf = new char[XXX];
int n = Win32.GetEnvironmentVariable("PATH", buf, buf.Length);

XXX is the buffer size for enviroment PATH,and my PATH is too long to filled in the buf,

I change XXX up to 8096 and Everything goes well.