Long time ago I had this issue - but for the love of God - I don't remember how to fix it and 3 hours of search didn't cut it.
I have a map - which consist in 5 monitors all aligned horizontal. The "add web resources" puts the new map on the dashboard - but it does not look good. It is actually too tall for waht the map looks like. Is hard to explain who I have without seeing the pic.
What I want is - what file I have to modify to be able to change the height of the opening for the map
1. Open "<install dir>:\SolarWinds\ipMonitor\internal\js\si_webr.js" in Wordpad
2. Find the following line (search for 300):
var height = _minictx.height ? IPM.ui.topx(_minictx.height) : 300
3. Change from 300 to your desired value and save file.
4. Refresh Dashboard and you should see Map resource update with new size. May need to force a refresh, CTRL F5. You may need to play with height value to get what you're looking for...