Just did a quick glance, first thing I found is following article from English version of Polish newspaper Gazeta Wyborcza.
It seems to imply that not only Poland has 122mm cluster munitions (probably meant to be 120 mm mortar - see below), but also 98mm for mortars and that there were allegations of its use in Afghanistan.
http://wyborcza.pl/1,86871,5674037,P...ter_Bombs.html
The 98mm round contains 9 submunitions, the "122mm" (whether it is 122 or 120) 15; in both cases it seems it would be HEAT-FRAG.
EDIT2: Seems the manufacturer is exaggerating "a bit" the effect
Will try to find more.
EDIT: Ah, here is a manufacturer's catalogue, listing cluster ammunition for 98mm and 120mm mortars, so maybe the article had the caliber wrong, but the mortars part right. The catalogue doe not have CM for 122mm, either rocket or gun.
http://www.unhcr.org/refworld/pdfid/48d748f723.pdf
Will try to search yet more.