Pages 09 extremely slow

I have both the new Pages (5.5.2) and the old Pages (4.3) from iWork 09 installed. I am running 10.10.3.

In the past few weeks, I noticed that the save dialogue has become unbearably slow in expanded form. Sometimes, it may take up to 10 or 20 secs just to load a folder. It doesn't seem to matter how many items are currently in the folder. I tried 1 folder with 44 items, one with no files in it at all. So it's not a problem of rednering previews or anything like that. But in collapsed form, the save dialogue works much better.

I'm on a 2013 rMBP with SSD, so it's generally very speedy. The new Pages (5.2.2) is perfectly responsive in these cases. I tried verifying the disk and repair permissions to no avail.

And I just noticed this in the past few weeks, so I think it may have something to do with software, but am unsure of what exactly.