Exported font position and size

I’m editing an existing font by removing some glyphs to reduce file size for use on the web. When I export the .otf and convert it to .woff the position of the characters change and the font appears blurred.

I don’t think it’s the conversion that is a problem. Is there something in the export from Glyphs that would effect the position or size of the characters?

Any help with this appreciated. I’m using the latest trial version.

What version of Glyphs do you have?
What was the format of the original font (TrueType or OpenType)?
Where do you test?

It is not a good idea to use Glyphs just for subsetting. Not all information is imported. There are tools that are specialized in subsetting, e.g. http://www.fontsquirrel.com/tools/webfont-generator has a subsetting option.

I’m using glyphs 1.4.3. The original format is TrueType, unfortunately I don’t have the OpenType. After exporting the .otf I’ve converted it to .woff, .eot etc using online tools. Then tested in browser locally.

I’d looked at fontsquirrel but not spotted the subsetting option in expert. I’ll try that out as it may be more suitable for the task.