Got my Office upgrade a few weeks ago, which made me happy because I was hoping it would obviate most of my need to run Windows XP in VirtualBox. While it has done that, Excel in particular also has a number of annoying and stupid problems. Here's my list.
No pivot charts.
Limited pivot-table sorting. The Win version of 2007 lets you do lots of fairly complex sorting on various items in the pivot table. Edited to add: OK, looks like you can use the sort button in the ribbon for sorting in other columns. Fine, but different from Windows and why include that sort option in the pop-up then?
Click on the pivot-table button to have Excel make a table for you and it puts it in a new sheet. Fine. But that sheet is inserted before the current one. Really.
Same auto-create also leaves the floating info window for pivot tables open every time.
Ugly, partially transparent, white on black floating windows in filtered and pivot tables.
Missing "clear" button to get rid of all the filtering on a table at once. Instead it's in the Data menu.
Incomprehensible menu customization process.
Window re-sizing when windows are put in background.
Window re-sizing upon copying a chart. The original size is restored, but still, what is going on?
Still doesn't use the standard clipboard process, so you get asked whether you want to save large clipboard upon quitting, and items cut don't disappear right away, and the copied range will be forgotten if you don't use it right away. (Actually I don't know what set of actions will wipe out the clipboard, but it seems like most of them.)
Calibri? Really? (OK, this is in Windows too.)
Modal dialog boxes in Find/Replace that close with a button that says "Close" instead of a red close button or a cancel button.
No default key combo for Replace.
Ugly pastel built-in chart types. (Again, Windows too.) Can they not hire someone with some taste over there in Redmond?
The red button stoplight button does not always get the black dot at its center when you've changed the document. [Added 15 April 11]
Some files are changed just by opening them and Excel will ask if you want to save them when you try to close. [Added 15 April 11]