Illustrator

• You can make a (fake) 'multiple page' layout in Illustrator:
Make a new document and set the page size to x times the amount of pages you want to have. So for 3 A4 pages in portrait mode next to each other you give the document a width of 630 mm (3 x 210 mm) and a height of 297 mm, Orientation: Landscape. Next go to Print. Set in General the Orientation to Portrait and move to Setup. There you choose in Tiling: Tile Full pages. Click on Done. To see your print sections click double on the Page Tool. That's it. You will see that the sections are also numbered!

• Cutting straight through an object with the Knife tool:
Before you do the cut, press Shift + Option/Alt. Keep them pressed while you cut through the object.

• Adobe Illustrator behaving weirdly can often be solved by deleting the Illustrator Preferences file. See in this Designorati page.

• How to edit startup files in CS3. Use the Document Profile files you can find in the following folders:

MAC:
Username/Library/Application Support/Adobe/Adobe Illustrator CS3/
New Document Profiles

WINDOWS:
C:\Documents and Settings\Username\Application Data\Adobe\
Adobe Illustrator CS3 Settings\New Document Profiles