Hi moonraker!!
Yes, that area can be a bit of a sticky wicket and has cause many players problems.
Try choosing your smallest character to lead your party and wiggle around as you go. IF you still cannot get through - well, you really don't have to. What is at the end of that passageway is the snake idol which will give you access to the Book of Servants in the library. This book has the replies you will need in the ritual BUT they're posted in the BEST TIPS thread!
Hope that helps!
Wyv