How to put a RF1100-232 into sleep mode


I have a RF1100-232 wireless module. It works nicely.
Because it is used in a battery powered module I like to get it into sleep mode.
The module consumes normal about 24mA, in sleep mode it uses 200uA.

However I have trouble to get it into sleep. DigitalWrite HIGH/LOW on the sleeppin
does not seem to work.

Description: yesyes DIY and astro :: RF1100-232 RF 433MHz Transceiver Module
I have contacted the write of the article above. But got no solution.

A tried an alterative to power it from the arduino. Because it only uses 24mA it should be powered from
a digital pin. Connecting the VCC to a pin and make it LOW before the arduino goes into deep sleep wont
work either.

Any suggestions?