Even channels not working in Maplestory?

I switched to a new ISP and new router, and since then I can't use even-numbered channels, and Cash Shop and MTS work only sometimes.
I can login or cc into them, but after that I get hit with major lag, usually resulting in timeout disconnect.
I know that the difference between odd and even channels is the port used, 8585 vs 8586. CS is port 8788 and MTS is 8990. CS and MTS also seem to have their own servers, but the even channels are on the same servers as the odd ones. So the problem isn't the server/IP-address, it's the port.

However, I do not know how to use this information to solve the problem.
Can anyone help?

Bump because I too have the same issue, is your ISP by chance Bezeq?

Actually, no. I used to have Bezeq and Golden Cable, with an Edimax wireless router, and all worked fine.
Now I have Hot, Netvision, and a TP-Link router, and I'm having the problem.

Edit: connected the old router, problem persists. So it's either Hot or Netvision, not the router. The odd thing is, before the Bezeq, I used to have a "slow" (1.5Mb) Hot/Netvision connection and it worked just fine. Now it's upgraded to 5Mb or some such, but the even channels stopped working :-(

in that case I guess I can write out bezeq as being responsible for this. but that doesn't help much.

I hear this happens to a lot of people who play from isreal or around there (Not a joke). The only way they found a work-around was to use a different ip or something (Like AOL)

I hear this happens to a lot of people who play from isreal or around there (Not a joke). The only way they found a work-around was to use a different ip or something (Like AOL)

confirmed, AOL does let you go to Even ch's however the second you try to party someone the lag becomes unbearable.

still looking for a way to fix this.