Help to free just 2 MB space of internal memory

Hi:
I have the Sony T1 rooted with AMR and app2sd of Rupor.
I'm very happy with it and with all the apps I have installed, but my problem is I'm getting this warning of "not enough space" and its corresponding ugly icon, as soon as the free internal memory is 4 MB or lower. If it is 6 MB, there's no problem at all.

Well now the Sony has 4 MB of free internal memory and I'm desperate trying to search a little bit of space.
I already did before a Wipe dalvik cache, using andromizer, and got some free space.
These are the apps I have installed (Moon+ Reader, Mantano, Repligo reader, aard dictionary and Goldendict ) and I would like to keep all of them. I don't want to uninstall any of them just to get rid of the warning.

I've searched through the folders of internal memory, but I can't find anything to clean or delete. I found some fonts (in EBOOKS\FONTS folder) that are 10 MB, like the SWNMTeb.tcc, but obviously I can't delete it, because it's part of the system or something.

I would appreciate very much some help.
Thank you in advance.

P.S. I must say that I already tried the Link2sd trick, but it didn't work for me. IMO the app2sd of Rupor is better, but it has its limits (2 MB limit in my case)