Help: Problem with MTU.

[cabrinha]

I have the modem usr 9105 with the firmware 2.5 and function in a pstn line. After the renewal of my adsl subscription I observed that despite the change from 384 to 512 the speeds were not satisfactory. After enough search I realised that the mtu is set to 1452 and not to 1500 (I use pppoa protocol). I tryed therefore various ways to change the mtu not only with programs that intervene in registry but also making changes myself directly in registry. Also I checked the mtu not this time by testing my computer but another one that i have. The result was the same. Consequently the problem emanates from the modem. Despite the fact that I set the modem's price to 1500 the result is the same (mtu stuck at 1452). Today I tryed an other modem and my connection was spitting fire. Speeds around 58-59 from greek major ftps. And the mtu set to 1500.
What can cause the problem? Is my modem problematic? What could I make?

Thanks in advance for any help given and truly sorry for any grammatical and syntactic mistake I did.

[cabrinha]

Noone?

[kinkymaster]

Kalispera filaraki....... pistebw eisai apo ta meri mas apo oti blepw........ pes mou ti sindesi exeis?

[cabrinha]

H sundesi einai hol 512-128 flat rate.

[mccoffee]

it's probably on ur modem and some providers limit mtu to capp your speed what modem do you own?

[kinkymaster]

geia soy filarako.......... kai egw hol exw, alla min anisixeis, apla i hol kleidwnei to MTU tis sta 1452 kai esi enw to bazeis 1500 sta analyser sou bgazei 1452.
An thes kapoia boitheia gia na stiseis kala tin grammi sou........ pes mou.