[javan]

Can someone explain the summoning limit in IWD to me?
While in the Dragon's Eye my cleric tried to Animate Dead but I got the message "summoning limit reached". (OK this was the third or fourth time in a row he cast the spell) My mage then tried Monster Summoning I - "summoning limit reached" message again. The bard tried the Horn of Vahalla - same message. I retreated the party and rested them for 24 hours. I tried to summon undead again but got the same message again. Aaaargh!
I uninstalled the game to make some room on my hard disk. A few days later I reinstalled the game and loaded a save game. Summoning was back to normal...

What is the limit that a spellcaster can summon? Does that limit affect other spellcasters in the party? Does the limit reset after sleeping/moving to another area/saving-reloading?

Thanks for any advice...