Other way to a not supported inverse laplace transform with maxima?

Hi,

I'm trying to calculate the inverse laplace transform of the following
equation and it doesn't seem to work:
ilt((15*%e^(-3*s)+15*%e^(-2*s)-15)/(2*s^2+4*s+34),s,t)

It is said it the documentation that "expr must be a ratio of polynomials
whose denominator has only linear and quadratic factors.". As far as i know,
(2*s^2+4*s+34) doesn't have "real quadratic factor".

Is there any other way to deal with that kind of operation with maxima (dev.
version or an extension)?

Thanks,

-- 
Benjamin Vanheuverzwijn

Google Talk/Jabber - bvanheu at gmail.com
http://vanheu.ca