I presume the increase in frequency of out-of-sync errors when climbing ladders and entering/exiting vehicles has been mentioned elsewhere, since it happens a lot.
There's an issue when jumping off buildings on to vehicles. Been mentioned?
If one jumps off a building and there's a vehicle below, one remains suspended in mid fall and passes very, very slowly over the vehicle until one drops to the other side.
Here is a screenshot of one case. I jumped off the building, was suspended in mid air and then a couple of other players jumped down and were also trapped. I was stuck the longest, for about a minute, enough time to have a conversation in chat before my feet touched the ground. In the screenshot, the vehicle has disappeared, so it's the three of us hanging there in mid air.

While playing today, on the ground I came across a couple of items of loot, called "grenades" and written in the blue colour reserved for rare weapons (and sandbags for some reason). In my backpack, they appear as AK-47s but are in the explosive item class. Here's a screenshot:

I haven't tried throwing them yet. Maybe AK-47s will be thrown, although I don't feel they will be that effective on the battlefield if used that way.
I am storing them in my stash. Since my stash is currently experiencing difficulties, as mentioned in another thread, I am starting to consider the possibility that these "grenades" may have some sort of voodoo properties and have somehow hexed my stash.
It's possible this is related to the other mysterious enigmas of the RWR world, such as the tractor and the strange dance the Brownpant officers do around the big radio towers when no-one's looking.
The plot thickens...