Units Drowning in Deployment?

I was besieging Mytilene as the Romani, with my fullstack at the southwestern corner of the city. That tile was the only one between the city and the sea. Attacked by a relief Macedonian fullstack of slingers, I opted to fight the battle. I loaded the battle, and was horrified to discover that the battle map had a large patch of sea intruding into my deployment area, instead of the deployment conforming to the coast! My mercenary Leuce Epos, on the extreme left flank, had deployed into the water, and without even doing a single thing I discovered that I had lost almost one entire unit of horsemen.

https://img162.imageshack.us/img162/7714/00879my.jpg

Is this a battle map error or something?

Pretty cool screen shot. I like how 12 guys survived because their heads stick up just above the ocean surface (apparently their horses are using invisible snorkels). Couldn't say if it's a battlemap issue.

Silly gallic cavalry, doesn't know how to come in out of the water.

Surprised the 1.2 coastline bug didn't cause it to have a blocky coast.

I wasn't surprised that there wasn't a blocky coast, because that sometimes happens. It's just that usually in this case the boundaries of the deployment area would conform with the coast instead of sticking out into the water. So yeah, i personally felt this was a battlemap thing. Just to see how many casualties I could get from accidentally deploying into the water, I reloaded the battle, then stacked all my units into the water. I tell you, no pack of lemmings could do better. I lost my whole army before I even clicked 'start battle'.