"We are working 24/7 and expect normal operations within 48 hours. Lesson learned... No fancy launch event for Megabox ;-)," he said.
MegaBox is an online music platform being developed by Dotcom and is expected to be launched later this year.
Mega attracted over 500,000 users on Sunday, when Dotcom hosted journalists and other guests to his Coatesville mansion for the website's launch event.
"If I would tell you how many signups we had since the launch you wouldn't believe it. I can't believe it. So, I won't tell," Dotcom also tweeted this morning.
A potential cloud on the Mega horizon comes from a Melbourne-based anti-piracy group, which is going after Mega's 'resellers' - those taking payment for the various mega storage options.
The group is called "StopFileLockers" and is headed up by Australian man Robert King.
King has not minced words on Mega's founder, Kim Dotcom, saying on the StopFileLockers website that "If Kim Dotcom believes that he can avoid the scrutiny of major payment services by using this thinly veiled reseller scheme then he is sorely mistaken."
This runs counter to the stated rights holder-friendly philosophy of Mega, which has them operating a full-time legal team who are said to be working to ensure that Mega complies with legal obligations from copyright holders.
Although it is early days, it appears that StopFileLockers is targeting Mega resellers' PayPal accounts which it wants to either terminate or freeze.
According to the StopFileLockers website "There would be little possibility of Paypal working directly with any Kim Dotcom owned file sharing business,". The impact of this on Mega's 10 or so resellers could potentially be disastrous as a closed or frozen PayPal account could significantly disrupt its businesses.