I actually just started using BB Messenger with two days ago and I pull my battery daily just because.. Shes still my one contact and my whole conversation from the past couple days is still intact..
In fact it just beeped a second ago new message..

Regarding the fonts.. I HATE the new address book. The fonts used to be smaller, and was the same size as the Call Log. Now its huge and every contact name entry is like 1/2" tall and Ive only got like 6 on screen now where before the font was smaller and I saw like 20 names on screen at once.. I dont think anything Ive done reduced it either. Only setting for font size Ive found made the browser impossible to read.. Didnt affect anything else on the Curve..