Well about the overloading..
I Just looked at the server load and it shows : Server Load 2.98 (4 cpus) (i really dont know if thats mutch but it doesnt seem to be mucth to me)
And they dont put so many sites on a server (at www.whois.sc/hostxl.net you can check ik) Reverse IP: Web server hosts 69 websites (reverse ip tool requires free login)

I Also send them a support ticket:

This is the second time in a month that de server has HUGE down time , what is it with that thing? .. why not change 99.5% Uptime! in 90% or something .. im really mad about the constant huge downtime this month!.
This is not what you garantee (99.5%) .. how are you gonna compensate this and where is the uptime monitor gone?

Regards,
Webmaster Taz-Mp3.com

And i will post there reaction as soon as i have it.