Cosmos 217 was the fourth flight of the IS antisatellite. It was launched on 24.04.1968 by a Tsyklon-2A.
TASS announced followings orbital parameters : 396km x 520km x 62,2°. But Western observers found the satellite in a lower orbit (144km x 262km). See for example :http://www.svengrahn.pp.se/histind/ASAT/GPRAF1.htm
The satellite reentered only two days after launch, so it confirms that Western data were correct. Many sources assume that the launcher suffered a failure. But I think it is quite more complicated.
For the first two flights, which used Polyot (11A59) launch vehicle, the launcher put the IS on a ballistic trajectory, and the orbital insertion was made by the IS himself.
If I understand correctly the Polyachenko's book (page 105), it was the same for the launch of Cosmos 185, the very first launch of Tsyklon-2A. So, I guess it was also the same for all subsequent IS flights on Tsyklon-2A and Tsyklon-2.
So, I conclude that the wrong orbit of Cosmos 217 was due to a satellite engine failure, and not to a launcher failure. Does anyone has any document which could confirm (or not) this theory ?