Running CB 1.2.5-R3.0-b2203jnks with Dynmap version 0.39-1163 with the following config;
Player markers and spawn markers are shown and working on the map.

I also get the following when DynMap starts;
18:50:49 [INFO] [dynmap-mobs] version 0.18 is activated

No errors anywhere to be found :(

dynmap-mobs configuration

update:
period: 5.0
resolution: 1.0
hideifshadow: 4
hideifundercover: 15
mobs:
creeper: true
skeleton: true
zombie: true
blaze: true
ghast: true
silverfish: true
slime: true
spider: true
wolf: true
zombiepigman: true
enderdragon: true
snowgolem: true
cavespider: true
spiderjockey: true
enderman: true
cow: false
pig: false
chicken: false
squid: false
sheep: false
villager: false
mooshroom: false
tamedwolf: true
ocelot: true
cat: true
golem: false
layer:
name: Mobs
hidebydefault: false
layerprio: 10
tinyicons: false
nolabels: false
minzoom: 0

Update
I've just got a few monsters showing; creepers, skeletons, zombies, enderman and spider.

However, they are most random and not very accurate and there are far more mobs that arent shown at all.
Can it be fixed? So that they show up faster than what they do now?

..Further update
With the following config they all seem to show up, but it takes a few minutes before they start to show..

dynmap-mobs configuration

update:
period: 2.0
resolution: 1.0
hideifshadow: 0
hideifundercover: 0
mobs:
creeper: true
skeleton: true
zombie: true
blaze: true
ghast: true
silverfish: true
slime: true
spider: true
wolf: true
zombiepigman: true
enderdragon: true
snowgolem: true
cavespider: true
spiderjockey: true
enderman: true
cow: false
pig: false
chicken: false
squid: false
sheep: false
villager: false
mooshroom: false
tamedwolf: true
ocelot: true
cat: true
golem: false
layer:
name: Mobs
hidebydefault: false
layerprio: 10
tinyicons: false
nolabels: false
minzoom: 0

This plugin seems to work without any problems... :|