IMSL Bessel function dbsk1() OK in DEBUG, CRASH in RELEASE

[intelgg]

I am using CVF 6.5.A on Win2K/P3 and am using
IMSL's First Order Third Kind Modified Bessel
function dbsk1().
It works in the debug build but crashes in the
release build with error
run-time error M6202: MATH
- log: SING error.
The value I pass to dbsk1() does
not seem to matter: dbsk1(1.0_8) and dbsk1(10.0_8)
behave the same way.