I had the same issue as the OP, so I calle IDM last week, and they told me about their Fair Use Policy, although they didn't explain the reason of the speed slowdown well and told me to call customer care for complaint, as the change was implemented without prior notice.

So when I was about to send them an email, I noticed that on their Terms and Conditions:
Service Modification
IDM reserves the right to modify or change its services' price content without prior notice according to the market requirements.


Now I rarely read Terms and Conditions, but for this seems pretty unfair for customers!

As for the Fair Use Policy this is how it works.
HOW DOES THE FAIR USE POLICY WORK?
IDM will be monitoring the network and tracking Internet bandwidth use (capacity and not content) for each subscriber account over time, and will be dynamically computing the average subscriber consumption per day and per month for all subscribers of the same account type.

If an account’s usage exceeds the limits IDM deems fair and reasonable for a residential broadband service during given periods, these limits being THREE TIMES the computed average subscriber consumption for the subscriber’s specific account type, IDM will apply daily and monthly speed limiting restrictions during these periods to the account in question, where daily limiting restrictions are reset every day and monthly limiting restrictions are reset at the end of the subscription’s billing cycle. If the usage for this account continues to be very high during these periods, IDM reserves the right to modify or stop the service (or any part thereof), either temporarily or permanently, without any prior notice.
Note that my consumption last was less 40GB only on a 1Mb unlimited plan!
I'm pretty pissed off about this new FUP, and probably will be changing to Sodetel soon.
Dude sodetel is worst trust me.
I've been downloading for about 3-4 days continuously. Every night I download for about 1-1.5gb and my speed didn't change. I know I'm not downloading that much, but the way they stated the FUP terms, like downloading a lot of songs or uploading videos as they mentioned, will make my 1gb per night seem an extreme over usage to them, and yet my speed didn't change.

All ISPs have FUP except ogero, but what differs is that some ISPs really crack the hell out of the customer when they apply it, and others really just apply it in a simple way, like till now I'm not finding any change in the quality or speed then last month or the month before.
If you find yourself unhappy and made your choice to leave idm, just go for ogero, they are the best.
gamer4life Thanks for the advice, but I'll be calling Sodetel to check about their FUP, and see if any applies. And I'll be considering Ogero, I'll take a look at the feedback threads.
IDM is driving me crazy those couple of weeks, the internet speed get reduced to nearly 256Kbps! And sometimes Http to even less!
Today my monthly subscription was reset, and even though it's the first day, they reduced the speed to 256Kbps, like 5 hours ago. My consumption so far for the day is nearly 1.7 GB. Seriously who has an Unlimited plan and doesn't download on average around 1GB/day at least. Their FUP states clearly that it'll be applied if the user exceed 3 Times the average consumption.

I tried to call them no one is answering. I know they have usually a very comprehensive customer service but they're breaking ma balls man.

EDIT: Just got off the phone with IDM tech support, their great customer support makes you never want to leave seriously (so does the waiting period between the transition from an ISP to another) and I guess I'll be trying the 4Mbps 50GB plan next month and see how it goes.
It's really weird in your condition. Your facing something more than FUP because it's really not normal what happened after your monthly renewal.
Yes I think it's better if you change from unlimited to a normal plan, than decide whether you stay with idm or not.
Anyone facing frequent disconnections today?
Yes I am. Probably Ogero doing maintenance.
Where do you live? i am in Mazraa and the connection today is not sable at all, the modem is loosing sync frequently..
I'm in Tabarja (Kfaryassine CO)
No disconnections for me but an unstable ping. I live in Adonis.
It's 2:43 in the morning, and instead of having the supposed 2M, my speed is now 0.5M :P anyone noticed this?
i still havent got the upgrade neither in speed nor in quota... although the customer care confirmed to me YESTERDAY that upgrades will be done today...
kfc wrotei still havent got the upgrade neither in speed nor in quota... although the customer care confirmed to me YESTERDAY that upgrades will be done today...
What was you old plan? And what new plan ur waiting for
sailor wrote
kfc wrotei still havent got the upgrade neither in speed nor in quota... although the customer care confirmed to me YESTERDAY that upgrades will be done today...
What was you old plan? And what new plan ur waiting for

1mbps/5gb --> 2mbps/45gb
the technical support just told me upgrades will be done this afternoon.
I got the quota, but my speed is still less than 1M.
gamer4life wroteI got the quota, but my speed is still less than 1M.
Did you ask why? Do you live far from the central?
No, I'm very close to the central. I'll ask them right away and get back to you.
Good luck hehe . i got not
I've been calling them since I told you, till now the line is busy, they don't even put me on hold.
I just got the quota upgrade but speed is still 1 mbps